[qca-gnupg] improved gpg binary search
[qca-gnupg] improved gpg binary search

gpg binary can be named gpg or gpg2 name (gpg.exe or gpg2.exe on Windows)
First search in application directory. Then on Windows lookup for
'Install Directory' key in paths:
HKCU\Software\GNU\GnuPG
HKCU\Software\Wow6432Node\GNU\GnuPG
HKLM\Software\GNU\GnuPG
HKLM\Software\Wow6432Node\GNU\GnuPG.
In the last search in PATH environment. On Mac OS X also check
/usr/loca/bin and /opt/local/bin.

svn path=/trunk/kdesupport/qca/; revision=1357590

sladage/qca,highfidelity/qca,karolherbst/qca,Bjoe/qca,sladage/qca,JoshuaKolden/qca,Bjoe/qca,highfidelity/qca,oktavarium/qca,oktavarium/qca,sladage/qca,JoshuaKolden/qca,JoshuaKolden/qca,KDE/qca,karolherbst/qca,Esf-Software/qca,karolherbst/qca,KDE/qca,karolherbst/qca,highfidelity/qca,Esf-Software/qca,KDE/qca,highfidelity/qca,JoshuaKolden/qca,KDE/qca,sladage/qca,Esf-Software/qca,Bjoe/qca,Bjoe/qca,oktavarium/qca,oktavarium/qca,Esf-Software/qca