Provide Emacs-IDE as a package (eide)

Add package information (in eide-pkg.el and the header of eide.el).
Add autoload on themes to add installation path to
custom-theme-load-path.
Add autoload on eide-start, to avoid requiring eide package in
.emacs.
Provide scripts to easily build and install eide package.

Convert INSTALL and AUTHORS to reStructuredText.

Signed-off-by: Cédric Marie <cedric.marie@openmailbox.org>
Remove default face height from color themes

Default face height is a personal preference and should not be set in
color themes.

Signed-off-by: Cédric Marie <cedric.marie@openmailbox.org>
Create eide-browsing theme

Remove eide-custom-tags-case-sensitive option and create a new theme
(eide-browsing) with tags-case-fold-search standard option.

Update configuration section in README.rst, with more details about
customization and themes.

Signed-off-by: Cédric Marie <cedric.marie@openmailbox.org>
Update install-package with package-initialize

Mention "(package-initialize)" - to be added in .emacs - in package
installation instructions.

Signed-off-by: Cédric Marie <cedric.marie@openmailbox.org>