Changeset 1299ea5b49 in tspsg for help/html/en/about.html

Updated version info to be set based on git tags.

'git describe' is now used for version definition. Major, minor and
release are taken from the latest git tag. Build is defined as number of
commits since the latest tag. If we're out of source, then .tag file
should contain output of 'git describe --abbrev=40' command.

Also, moved version related code from tspsg.pro to version.pri.