(eproject--search-directory-tree): Do not walk through ignored dirs

Plus a small optimization of never calling `file-directory-p` twice.
Allow eproject to work not only with dired-mode, but also with modes derived from it.

See https://github.com/escherdragon/sunrise-commander/issues/9 -- this is an
issue reported by a user of the Sunrise Commander who happens to be also an
eproject user. SC has major mode `sr-mode' which is a mode derived from
dired-mode.
Fixed the end of string in `auto-mode-alist` regexp.

`$` could match a newline whereas `\\'` cannot.
Merge pull request #24 from dudebout/patch-1

Fixed the end of string in `auto-mode-alist` regexp.
Do not redefine anything-for-buffers
Add autoload cookies in eproject-anything.el
Autoload eproject--project-buffers

Otherwise, autoloading functions/variables in eproject-anything
does not work unless eproject-extras is loaded explicitly.
Fix compilation warning in eproject-anything.el
Do not modify global key in helm-eproject.el

Instead, eproject-helm-configure is added.  User can call this
function when s/he wants to use the original configuration.
Add generic-hg/bzr/darcs project types
Fix commentary in eproject-anything.el
Updated helm-eproject

- Use helm api functions for finding files.
- Change the heading to something more like other helm headings.
- Removed trailing spaces.
Merge pull request #23 from escherdragon/master

Check for modes derived from dired-mode rather than only allowing dired-mode.
Merge pull request #25 from tkf/fix-eproject-anything

Do not redefine anything-for-buffers
Merge pull request #26 from tkf/eproject-helm-configure

Do not modify global key in helm-eproject.el
Merge pull request #27 from tkf/vcs-types

Add generic-hg/bzr/darcs project types
Merge pull request #28 from thomasf/helm

Simplified helm-eproject
Merge pull request #20 from dgutov/master

Do not walk through ignored directories
just call it "compile command"
Add eproject-tasks.el (source-based task definition helper)