Minor Menu Fixes

AC_U: Stub functions, used if EULA agreed

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

Update the stub code of BOSS