Revert removing TakeCover from Shock Trooper and make them Crushable
Make mrj not jam allied missiles
Closes #4463. Added Shrapnel, as well as variable velocity and arc for bullets
Edited CHANGLOG
update to .NET 4.0
Migrate to System.Lazy.
Merge pull request #5048 from Unit158/shrapnel

Shrapnel
Merge pull request #5071 from ScottNZ/winmake

Added a counterpart to the Makefile for Windows users
Merge pull request #5070 from ScottNZ/mrj

Make mrj not jam allied missiles
Merge pull request #5069 from cjshmyr/shok

Revert removing TakeCover from Shock Trooper and make them Crushable
Reduce hijacker hp from 80 to 50
Merge pull request #5082 from pchote/dotnetfour

Upgrade to .NET 4.0
Increase ra husk hp from 140 to 280 and increase burn damage
decide which mirror to choose locally and display result

closes #3904
Merge pull request #5086 from ScottNZ/balance

More RA balance tweaks
clean up after MonoDevelop/Visual Studio
Update INSTALL

* .NET 4.0 #5082
* SDL 2 #3315
* avoid trademarks
Update INSTALL

we now require a .NET 4.0 compatible compiler
Minor explosion weapon sound fixes
Adds Explode weapons for ships and submarines