SkirmishControl & SkirmishControlTool: include any *.sdd folder (located in datadir/games/) into mod selection list.

( made Skirmisher Tab able to read lua config/info file directly from *.sdd folder )
ExtrasTab/ExtrasToolTabs.cs: update it with all the fixes previously added into ChatTab's ToolTabs.cs.

ToolTabs.cs: just an extra precautionary code, in case new panel is added without color scheme
SkirmishControlTool.cs: add partial support for mission sdd just for completeness.
(Current limitation: it doesn't show any config options inherited from dependencies.)
And some fixes to the crude LUA table reader.

SkirmishControl.cs: fix duplicate sdd mod entry.
Merge pull request #299 from xponen/zkl_skirmisherAcceptSddFolder

ZKL: skirmisher now able to read *.sdd mods folder