g13: Move 'call-gpg.c' to common.
* common/Makefile.am (common_sources): Add files. * g13/call-gpg.c: Move to 'common' and adapt slightly. Add a parameter to let callees override the gpg program to execute. * g13/call-gpg.h: Likewise. * g13/Makefile.am (g13_SOURCES): Drop files. * g13/create.c (encrypt_keyblob): Hand in the gpg program to execute. * g13/mount.c (decrypt_keyblob): Likewise.
- Signed-off-by: Justus Winter <justus@g10code.com>