Adding NASTLH to the AI
added also gatech to the AI ...
Support ini files with spaces around the ‘=‘.
Add an early TS tileset importer and temperate tileset.
Added notifications for new objectives to scripted missions

Fixes #6692
Change indexes into tile arrays to be stored as bytes to save memory.

The index value needs only be big enough to handle all defined terrain types. This is a low number so we can save memory by defining it as a byte. This particularly saves memory for the CustomTerrain field in the Map class, which defines a cell layer for the map using tile indexes, so we can reduce the size of that layer 4x as a result.
Don't store pre-calculated texture coords in Sprite.

By storing only the four corners, we can save the object overhead of an array and 4 float elements per sprite. This results in savings of around 5 MiB to store these coordinates.
HashSet<byte> => BitArray resourceTypeIndices

BitArray can store 256 bits in 32 bytes plus overhead (pointer & length),
which gives it better memory locality too (<= 2 locations in memory).
Also, the actual count will be much less, probably at most around a dozen.
This might not impact performance, but the AI is dumb & HashSet<byte> is
clearly inefficient.
Changed Vertex constructors to pass more parameters as plain floats.

This avoids callers having to construct a float2 struct, only to have the Vertex constructor unwrap it into individual components again.
Remove static state from ChromeProvider.
Remove obsolete PackageContents array from Manifest.
Disabled changing e7's stances
Load assets using absolute paths.  Fixes #6717.
Cache the support dir path.
Merge pull request #6722 from abcdefg30/disable_tanyas_stances

Disallow changing tanya's stance on allies01
build with previous latest mono 3.8
Merge pull request #6726 from Mailaender/travis-mono-3.8

Updated the release build servers to Mono 3.8
Merge pull request #6694 from LipkeGu/ai_update

[TS] Add Nod Stealth Generator and GDI TechCenter to the AI
Merge pull request #6724 from pchote/absolute-paths

Load assets using absolute file paths
Moved two more Orders from RA to Common