add skeleton Path class
use new Path class in scnOpen() and draw()
allow stacked units in scenario files
change Path arrays into lists (protobuf-net can serialize them)
use new path implementation when selecting units
draw unit selection bar again
reimplement selecting/deselecting units in unit selection bar
implement moving paths (but not moving only some units in stack)
implement making paths
add existence check when moving and other small edits
implement moving subset of units in path
add Path.selMinPos() and Path.selMaxPos() methods
right click on unit to stack paths
Merge branch 'master' into stacking
fix compile error after merge
apply Unit method renames to Path class
add back nonzero tight formation spacing
stack paths as they arrive instead of all at once
apply CmdEvts only to existing paths and units
reimplement making units (currently ignores resources)