check for null because clients may be gone already

fixes #3694
load mods on double-click

closes #3166
remove workaround for very old Mono bugs
officially bump the required Mono version to stable 2.10.X

closes #2597
those old Ubuntu/Compiz versions are not maintained anymore
Binary patch the OSX mono check to 2.10.0 for x86.
Remove obsolete ppc arch from OSX launcher.
Update the mono install prompt text too.
Update source code to match.
bump mono runtime version to 2.10 for Debian
use stream reader extensions for loading ra/cnc Terrain
StyleCop clean Map/*.cs files
More TS cursor sequences.
Adding Nod buildings matching current GDI tech tree (power plant, production facilities).
Improving Weapons Factory exit, enabling RallyPoint (so you don't have to move units out of the way manually).
Enabling ReamBuildings and Nod Helipad prerequisite for Nod aircraft.
Fix missing NAWEAP RallyPoint indention.
use StreamExts for LegacyMapImporter
Merge pull request #3744 from Mailaender/tileset-stream-exts

Ported Terrain parser to StreamReader extensions
Merge pull request #3738 from Mailaender/fast-mod-switch

Wired up OnDoubleClick for the ModBrowser.
Merge pull request #3695 from Mailaender/team-no-nre

Don't crash C&C ingame menu after player drop