Release v0.11-rc1

Changelog:
 * general fixes and improvements from Syria-at-War
 * mission-init: extend environment check (Closes: #213)
 * player: multicrew support (Closes: #169)
 * timer: add ability to start/stop a timer
 * ui: show breakdown of loaded weapons in payload check (Closes: #173)
 * region: detect the radius of the region
 * squadron: set any player slots airbase value if not set
 * subordinates: set all subordinates to dead
 * observable: map event id to event name
 * component system
 * region: create a region manager
 * asset manager: notify when new asset is added
 * systems: fix calling of postinit method (Fixes: adcbe02a61b3 ("systems: while restoring state ignore scenery events"))
 * systems: loop through systems in order
 * tests: remove some extraneous comments from runtests
 * tests: call test scripts through lua executable
 * theater: use standard Timer class in exec
 * theater: remove unneeded class attributes
 * theater: move pcall so commands cannot kill the command queue (Closes: #204)
 * stm: fix string format error
 * region: refuse to add templates meant for other theaters (Closes: #202)
 * initial commit of demo theater (Closes: #130)
 * settings: provide useful constants (Closes: #171)
 * settings: change default theater path (Closes: #38)
 * weaponstracking: reduce log level of some messages
 * tests: suppress some needless warning messages
 * assets: allow dct file to define the location of an asset (Closes: #158)
 * template: change airspace definition
 * utils: change centroid to be 2D only
 * vector: change vector initialization
 * asset manager: add getAssetByDCSObject method