add basic message/announcement sending API functions
add stubs for global API message sending functions
add basic location move API functions

* no implementation for Player.apiEndLocationMove yet (still unclear
  what this function needs to do in our setup; possibly player
  following, maybe it is not needed at all)
* slight change in Player.gsMoveCheck just so we don't need to call
  auth.getToken again in apiCheckIfNeedToMoveToAnotherGSAndGetMoveData
add item locking API functions (resp. stubs)

(includes necessary base functionality in model classes)
allow Item.setContainer to be called with current container

Item.setContainer can now also be used to (re)assign items to their
current container (used this way when moving items to different slots
within inventory/bags)

* adjustments to unit/func tests
* set default capacity (16) in Bag model class for the sake of
  simplicity (would have to explicitly set it in most tests working with
  bags otherwise); overridden by capacity values defined in GSJS
* increased JSHint "max statements per function" limit (it complained
  about Item.setContainer, which is not really overly complex yet, IMO)
add misc. API functions/stubs

Add various API functions that are required for basic game operation
(implemented where implementation is simple, or as stubs if the
necessary underlying model functionality is not there yet).
add missing basic item handling API functions
add global.apiIsPlayerOnline and .apiSendToGroup
enable skipped tests

Enable the functional tests that were so far skipped because of
missing model API functions.
Merge pull request #25 from yelworc/model-api-pt2

second batch of model API functions