Implemented IEquatable<T> to speed up equality comparisons.

Actor, CPos, CVec, WAngle, WPos, WRange, WRot and WVec structs now implement IEquatable<T> which means unboxing/casting costs can be eliminated.

Also simplified the ToString method by concatenating components directly rather than using a format string since the overhead is a bit high for simple cases like this.
Added MinBy, MaxBy, MinByOrDefault and MaxByOrDefault methods and replaced calls of the style OrderBy[Descending]().First[OrDefault]() which is not as performant.
Also implemented on the Bits<T> struct.
unbreak the OpenRA.Game.exe start menu link

fixes #5448
also watch master and next for deployment
we don't support SDL 1.2 anymore
replace libraries with SUSE Linux Enterprise 11 SP3 binaries
Formatting fixes.

Spaces to tabs, indents, etc.
catch trait lookup in constructor

closes #5472
Merge pull request #5461 from Mailaender/sle-libraries

Replaced libraries with SUSE Linux Enterprise 11 SP3 binaries
Merge pull request #5456 from Mailaender/travis-next-master

Adjustments to Travis CI
Merge pull request #5449 from Mailaender/nsis-lua-outpath-breakage

Fixed the OpenRA.Game.exe start menu link
Merge pull request #5412 from RoosterDragon/formatting

Formatting
move RallyPoint lookup into a Lazy
give concrete a color that is distinguishing from sand
Small Correction to one of the music names.

Taken from Frank Klepacki's Website
Merge pull request #5481 from Generalcamo/patch-8

Small Correction to one of the music names.
Changed logging in DoTimed/RunActivity to create less overhead.

- Refactored PerfTimer to use less memory.
- Avoid using the PerfTimer in highly called methods DoTimed and RunActivity, instead tracking long ticks manually to reduce overhead and avoid memory allocations.
- Added some helper methods in PerfTimer to output information when a tick takes too long.
- Changed PerfTimer logging to output the time at the start of the line, and no longer truncate output per line.
- Settings.LongTickThreshold changed from TimeSpan to float and renamed to LongTickThresholdMs.
Merge pull request #5480 from Mailaender/d2k-concrete-color

Fixed concrete having the same radar color as sand.
Add single-player mission 'Intervention'