added xlst transform to xml class.
updated copyright year.
Merge remote-tracking branch 'upstream/master'
fixed issue with wrong null checking of CC and BCC strings in Mail class
Merge remote-tracking branch 'upstream/master'
small cleanup
Merge remote-tracking branch 'upstream/master'
Added the possibility for the Shell.exec command to ignore some error codes.
Merge pull request #40 from JeroenVandezande/master

XLST transform