js2-mode-find-enclosing-node: Make docstring and impl consistent with name

Closes #170
Fix #171

* js2-mode.el (js2-parse-primary-expr): Use
`js2-current-token-end' to retrieve the end of the current token.
This works better if parsing errored on EOF.
(js2-read-regexp): Don't try to set `syntax-table' property (it
didn't work anyway, `syntax-class' is bogus).
js2-parse-primary-expr: Make some vars "more" local
Add imenu support for the Sencha framework

This implements issue #172.
Merge pull request #173 from lelit/master

Add imenu support for the Sencha framework
Indent before inequality operator at bol

Fixes #174
Support object destructuring inside arrow function args

* js2-mode.el (js2-parse-plain-property): Don't move too far when
there's no colon.
(js2-parse-assign-expr): Restore the previous value of
`js2-parsed-errors' after arrow token is found.

Fixes #167
Indent after `+='

Closes #174
create extra imenu items from simple regex

- imenu items created from AST are respected
- js2-extra-imenu-generic-expression has customizable regex
- imenu items failed to be created from AST is created by regex
- AngularJS supported
- imenu index could be manually updated by user