All "subclasses" of DiskArchive are splitted out. This class is useless

Now DiskArchive only serves for SDMC, then it should be just a "SDMCArchive"

ExtSaveData is more similar to SaveData, so let it be a subclass of SaveData

The error checking of SaveDataArchive is completely different from DiskArchive, so it has to be a new class instead of a subclass of DiskArchive.

Same as directory, file shouldn't expose Open either.

Open should not be an interface exposed by Directory because it is the Archive thats implement the methed to open the directory. The service API of 3DS also implies this - Open is not a function of directory service, but is of FS main service

and make the mode parameter a reference since it is a BitField union

Update Donation Info in Readme

Link main site donation page in readme instead of providing further donation info there.

NWM: stub Initialize with an error

Update CONTRIBUTING.md

Fix build on DragonFly and FreeBSD

Small fix to let IDA see target.xml

Citra SDL2 doesn't have a launcher, and citra.desktop tries to execute
citra-qt which is N/A unless built with ENABLE_QT. Limiting installed
files to one of the options also makes it easier to split them into
separate non-conflicting packages downstream.

/usr/bin/ld: ../common/libcommon.a(string_util.cpp.o): undefined reference to symbol 'libiconv_open'

In file included from src/common/microprofile.cpp:7:
In file included from src/./common/microprofile.h:23:
externals/microprofile/microprofile.h:830:5: error: use of undeclared identifier 'MP_BREAK'
    MP_ASSERT(t == nBegin);
    ^
externals/microprofile/microprofile.h:238:34: note: expanded from macro 'MP_ASSERT'
                                 ^
externals/microprofile/microprofile.h:831:5: error: use of undeclared identifier 'MP_BREAK'
    MP_ASSERT(nTimerIndex == (nToken&0x3fff));
    ^
externals/microprofile/microprofile.h:238:34: note: expanded from macro 'MP_ASSERT'
                                 ^
[...]

src/core/hle/service/soc_u.cpp:107:6: error: 'ENODATA' was not declared in this scope
     {ENODATA, 43},
      ^
src/core/hle/service/soc_u.cpp:117:6: error: 'ENOSR' was not declared in this scope
     {ENOSR, 53},
      ^
src/core/hle/service/soc_u.cpp:118:6: error: 'ENOSTR' was not declared in this scope
     {ENOSTR, 54},
      ^
src/core/hle/service/soc_u.cpp:139:6: error: 'ETIME' was not declared in this scope
     {ETIME, 75},
      ^

In file included from src/common/x64/cpu_detect.cpp:16:
/usr/include/machine/cpufunc.h:66:17: error: unknown type name 'u_int'
static __inline u_int
                ^
/usr/include/machine/cpufunc.h:67:6: error: unknown type name 'u_int'
bsfl(u_int mask)
     ^
/usr/include/machine/cpufunc.h:69:2: error: unknown type name 'u_int'
        u_int   result;
        ^
/usr/include/machine/cpufunc.h:75:17: error: unknown type name 'u_long'; did you mean 'long'?
static __inline u_long
                ^
/usr/include/machine/cpufunc.h:76:6: error: unknown type name 'u_long'; did you mean 'long'?
bsfq(u_long mask)
     ^
/usr/include/machine/cpufunc.h:78:2: error: use of undeclared identifier 'u_long'; did you mean
      'long'?
        u_long  result;
        ^
[...]

Most modern Unix environments use 64-bit off_t by default: OpenBSD,
FreeBSD, OS X, and Linux libc implementations such as Musl.

glibc is the lone exception; it can default to 32 bits but this is
configurable by setting _FILE_OFFSET_BITS.

Avoiding the stat64()/fstat64() interfaces is desirable because they
are nonstandard and not implemented on many systems (including
OpenBSD and FreeBSD), and using 64 bits for stat()/fstat() is either
the default or trivial to set up.

src/common/file_util.cpp:79:19: error: variable has incomplete type 'struct stat64'
    struct stat64 file_info;
                  ^
src/common/file_util.cpp:79:12: note: forward declaration of 'stat64'
    struct stat64 file_info;
           ^
src/common/file_util.cpp:99:19: error: variable has incomplete type 'struct stat64'
    struct stat64 file_info;
                  ^
src/common/file_util.cpp:99:12: note: forward declaration of 'stat64'
    struct stat64 file_info;
           ^
src/common/file_util.cpp:342:19: error: variable has incomplete type 'struct stat64'
    struct stat64 buf;
                  ^
src/common/file_util.cpp:342:12: note: forward declaration of 'stat64'
    struct stat64 buf;
           ^
src/common/file_util.cpp:359:19: error: variable has incomplete type 'struct stat64'
    struct stat64 buf;
                  ^
src/common/file_util.cpp:359:12: note: forward declaration of 'stat64'
    struct stat64 buf;
           ^
4 errors generated.

src/common/thread.cpp:90:5: error: unknown type name 'cpu_set_t'; did you mean 'cpuset_t'?
    cpu_set_t cpu_set;
    ^~~~~~~~~
    cpuset_t
/usr/include/sys/_cpuset.h:48:24: note: 'cpuset_t' declared here
typedef struct _cpuset cpuset_t;
                       ^
1 error generated.

src/common/thread.cpp:123:5: error: use of undeclared identifier 'pthread_setname_np'
    pthread_setname_np(pthread_self(), szThreadName);
    ^
1 error generated.

FRD: fix GetMyFriendKey

Fix typos