This allows users to specify whether each regex in NERDTreeIgnore should
apply to only files or only dirs.

this gives users a chance to filter out nodes using whatever logic they
please

Note that for directories, there is a trailing slash

when the user was prompted to choose a tree to mirror, it would mirror
the wrong one

this commit is a modified patch from Guillaume Duranceau

this commit is a modified patch from Guillaume Duranceau

allows the statusline to be customised for the nerd tree window

*remove the change log prior to v3.0.0
*remove the todo section
*change "about the author" to "about" and put the github/vim.org project
urls in it