Configured Grunt build system
fixed display error of toolbar button's dropdown mark on non-webkit browsers (IE, FF, Opera)
Merge pull request #450 from kyuri/upstream

fixed display error of toolbar button's dropdown mark on non-webkit brow...
Merge branch 'master' of https://github.com/vitmalina/w2ui
typos and a few semicolons...
Merge pull request #452 from GerHobbelt/patch-typos3

typos and a few semicolons...
Small changes
 fixed two code crashes in the demos and a minor simplification (Math.max() instead of compare+assign)

Resolved conflicts
unused local var removed
reduced duplication: w2layout used redefined sets of panel names everywhere; now a single (constant!) list is used for all; using the variable name `p1` where possible to strengthen the feel of similarity in the various code sections where this list is used. The one loop which only accessed 5 of the 6 panels known is tweaked accordingly.
Refactored $.inArray
stricter checks to prevent crashes (some of the demos crashed here too)

Merged
Removed dead code
Fixed merge conflics
strict check for the attribute to be function before executing it.

Otherwise similar to commit SHA-1: b8e25d2b4b162febbcbce73c0f2823afe7541f11:

* JS coding practices / JSCS lint check: code obj.field instead of obj['field']
Again, we don't care whether the `url` attribute is actually part of the instance options and null or undefined: when it is is either null or undefined it is unusable and for all intents and purposes 'not specified': another case of double-equal.
fixed crash in sidebar due to code expecting nodes[] to be initialized while it isn't yet (compilers would say: trying to use variable before its assignment/initialization); also simplified the rest of the node tree code as the demos b0rked in a few places in there.
observed some very odd use of an otherwise unknown this._tmp attribute which simply acts as local var; given the way it is coded it does not assist as a semi-global in the recursive method, so it can be simply replaced by a local variable. Searched the entire codebase and it does not surface anywhere else but in these places.
JS coding practices / JSCS lint check: code obj.field instead of obj['field']
typo fix which I missed in a previous extract