update `this.context` with data context on query calls
allow passing a function for maximumSelectionSize
#619 : val takes an optional argument to avoid triggering 'change'
fix scroll event handling since it doesnt bubble. also add a shim behind the dropdown, this allows it to properly close even when used inside modals. sometimes modals will place their own shim that closes the modal and aborts the default mousedown event. in such cases the modal would close but the dropdown element would still float on the screen now detached and the only way to close it would be to make a selection
fix highlighting bugs introduced by disabled option support. fixes #765 closes #775
Merge pull request #771 from phtrivier/issue-619

#619 : val takes an optional argument to avoid triggering 'change'
by default do not trigger change from val. #771 #619
Merge pull request #756 from socialceramics/url-function-with-arguments

Ajax `url` option (when function) now called with same arguments and context as `data` option
better support orientation change on mobile. #782
allow '0' vals to be set. fixes #646
use the dropdown mask to close open flyouts instead of a global listener. also move the original element off screen instead of hiding it so clicking a label focuses select2 instance
ignore configured placeholder on selects without first empty option. fixes #785
fix selectOnBlur when closed by means other then tab key. fixes #470
sync disabled and readonly statuses off original element even post creation
minor optimization. #787
fix more hierarchical selection bugs. fixes #775
added jquery plugin manifest
touched manifest to force a commit
disable focus-via-tab when disabled. fixes #614
improve placeholder management. fixes #712