CRM: Fix compare_version() to actually work correctly on a regular basis
As far as I can tell, it never worked, which is quite disturbing.

Some cases that were broken (old/incorrect rc -> new/correct rc):

• 1.0 ? 1.1 (0 -> -1)
• 1.0.1 ? 1.1 (0 -> -1)
• 1.0.1 ? 1.0.6 (0 -> -1)
• 1.3 ? 1.1.0 (-1 -> 1)
• 1.0.5 ? 1.0.6 (0 -> -1)
• 1.0.1 ? 1.0.8 (0 -> -1)
• 1.0.8 ? 1.0.1 (0 -> 1)

Mercurial revision: b7e2ee5847f85c0e08e617c456789d755c90aa1d