VMM/config: Updated Dovecot version check. Renamed function check_version_format() -> check_dovecot_version(). Now this function checks also if misc.dovecot_version >= MIN_DOVECOT_VERSION.

# use glob syntax.
syntax: glob

*~
*.py?
.*.swp
.swp
build
debian/vmm
debian/*.log
debian/*.debhelper
debian/files
debian/*substvars
.pc
*.egg-info