macosx/CAS: implemented full profile management, which is retained across sessions, allows custom profiles and even to delete the default ones, if desired

To restore the defaults, it is currently needed to reset the preferences.

This commit includes further ObjC2isms and some factorization

Thie fixes the following error.

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make.exe[1]: Entering directory `F:/lang/work/vlc/vlc.git/modules/access_output'
  CC     libaccess_output_file_plugin_la-file.lo
file.c: In function 'Open':
file.c:142: error: 'STDOUT_FILENO' undeclared (first use in this function)
file.c:142: error: (Each undeclared identifier is reported only once
file.c:142: error: for each function it appears in.)
make.exe[1]: *** [libaccess_output_file_plugin_la-file.lo] Error 1
make.exe[1]: Leaving directory `F:/lang/work/vlc/vlc.git/modules/access_output'
make.exe: *** [all] Error 2
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Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>