- Splitting the pull request in half.
- Added THRUREFLECT, MIRRORREFLECT, and AIMREFLECT. All require REFLECTIVE to work.
- THRUREFLECT prevents missiles from changing course if reflected, and takes precedence over all reflective flags.
- MIRRORREFLECT causes missiles to perform a direct 180 turn-around.
- AIMREFLECT turns the missile back to the original shooter, and does not slow the missile down.
- Added three missile impact pointer changing flags.
- HITTARGET, HITMASTER, and HITTRACER.
- A missile that dies hitting an actor will set this impacted actor as the new target/master/tracer, depending on specifications.
Added cl_waitforsave

- cl_waitforsave (default true) pauses the game timer when a save
starts, preventing the network buffer from trying to compensate for slow
saves.
Merge branch 'hitpointer2' of https://github.com/MajorCooke/zdoom

Conflicts:
	src/actor.h
	src/thingdef/thingdef_data.cpp
Merge branch 'waitforsave' of https://github.com/Edward850/zdoom
- Various CMake fixes for two problems.

1) Don't show OSX_COCOA_BACKEND option if the host is not OSX;
2) Don't use the '-msse' compiler flag in dumb/ if the architecture does not support it.
- Added Steam detection for Stife: Veteran Edition.
- Added Steam install scanning for Linux and OS X. (OS X and Win32 not yet tested.)
- Fixed: Extra Steam paths still need steamapps/common appended to them.
- Accidentally committed debuging code.
- Added rclamp(<int>,<int>).
- Usable for DECORATE expressions. Chooses one of the two numbers placed in the field.
- Renamed RClamp to Pick.
- Pick can now hold unlimited numbers to choose from.
- I.e. pick(1,4,12,16)
- fixed: FxPick leaked the array's content. Also did some cleanup on FxPick code.
- Fixed: The new HIT* flags were checking the wrong actor.
- Added flags for A_CheckLOF:
- CLOFF_SETTARGET | CLOFF_SETMASTER | CLOFF_SETTRACER
- An actor that causes A_CheckLOF (and only an actor) to succeed will set the intercepting actor as its target, master, and/or tracer, respectively.
- Added HIT* flag detection for bullet and rail attacks.
- Need to set it on the puff itself, not the defaults.