Round when calculating frame delay

This has no effect on the current max fps of 30, since 1000/30 rounds
down to 13. However, 1000/60 is ~16.6666, so we need to round that up to
get a more accurate delay.
Set max fps to 60 and cut default speed in half
Use parse_duration() for durations that weren't using it

Also, parse_duration() no longer accepts ticks. An integer value with no
suffix is assumed to be in milliseconds.
Convert real time to ticks for animations
Get active frames working and implement Bresenham for some frame timing

There are still problems with active frames when animations are too
short.
Try to handle active frames for fast animations
Fix occasional black lines between tiles

Closes #1059
Merge pull request #1091 from dorkster/fixes

Fix occasional black lines between tiles
Fix compile a error

I am compiling with gcc 4.8.2 here and this error comes up
/home/sb/OSS/flare-engine/src/UtilsParsing.cpp: In function ‘int parse_duration(const string&)’:
/home/sb/OSS/flare-engine/src/UtilsParsing.cpp:58:51: error: could not convert ‘(((float)((int)MAX_FRAMES_PER_SEC *  val) / 1.0e+3f) + 5.0e-1f)’ from ‘float’ to ‘FPoint’
   val = floor(((val*MAX_FRAMES_PER_SEC) / 1000.f) + 0.5f);

The UtilsParsing.cpp file included the UtilsParsing.h header file, which
includes Utils.h where floor() seems to be defined for FPoint.

So we still need to include the math.h which works for the floats
we're using here.
Merge pull request #5 from stefanbeller/60fps_fix

Fix compile a error
Merge pull request #1090 from dorkster/60fps

Lock the engine at 60fps instead of 30fps