Move definition of bb_got_signal to mingw.c

On POSIX platforms bb_got_signal is defined in libbb/signals.c; for
MinGW put the definition in win32/mingw.c.  This is better than the
Omit functions not required if seamless compression is disabled
Remove declaration of getpagesize
Don't store file details in inode hash table
Merge remote-tracking branch 'upstream/master'

Conflicts:
	archival/libarchive/open_transformer.c