Merge branch 'develop'
Merge branch 'master' into develop
Merge pull request #202 from techlivezheng/feature/find-hidden-file

Make NERDTreeFind work on hidden files
add Path.isUnixHiddenFile and refactor to use it
Merge pull request #203 from techlivezheng/feature/find-in-existing-window

Reveal the current editing file in current NERDTree window instaead initiating a new one
Merge pull request #204 from techlivezheng/feature/chrootcwd

Add a NERDTreeCWD command to change tree root to CWD
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' into develop
Fix s:Path.Resolve to it handles '/' properly
Merge pull request #213 from cperl82/fixes

Fix s:Path.Resolve to it handles '/' properly
Added a frequently asked question to README
Merge pull request #219 from felipebueno/master

A question asked by many VIM / NERDTree newcomers
decompose the giant NERD_tree.vim file

* Move the classes out into `plugin/nerdtree/<classname>`.
* Move the other functions out into `autoload/nerdtree.vim`.

Stuff still to do:

* extract out at least one view class from `autoload/nerdtree` -
  something like NERDTreeWindow
* figure out which functions in autoload/nerdtree should be scoped to
  the script instead of public
replace a script level var with a query
manually apply #220 to fix NERDTreeFind for hidden dirs
move KeyMap_Invoke into the autoload file

This will keep the class file cleaner, and may also fix #223
fix the <enter> mapping

It now acts the same as the ActivateNode mapping ('o' by default) again.
This was broken in the big refactor.

Fixes #222
some cosmetic updates to the class files

* fix the fold markers (they were unnecessarily deep)
* always have one line under each method
* update some of the fold comments -> always use FUNCTION in all caps
* add a modeline to each class file
fix a couple of function calls that should have been renamed

Call nerdtree#echo, not s:echo. This was changed in the big refactor.

Fixes #224.
extract the tree creation functions out into their own class

Add the NERDTreeCreator class.

Stick all functions related to creating a primary/secondary/mirror
nerdtree in there. We may break this down further in the future, but
this is a good starting point.

Make some of the interface binding functions in autoload/nerdtree
public. This is needed since we are accessing some of them from
NERDTreeCreator. Should be temporary until we get some kind of proper
interface binding system set up.