[#388] Custom LDAP filter

These filters change the implemntation of sub and gsub to use the block method.
This prevents the evaluation of backreferences in the replacement text. See
https://gist.github.com/1491437 for examples.

Also, it allows split to be called without arguments to split strings on
whitespace.

The floated tags (>toc and <toc) are invalid syntax because of the < and >
characters. We transform them to toc_left and toc_right instead.

This is required to retaiun the definition in development mode as the module
is stragely reloaded.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@8234 e93f8b46-1217-0410-a6f0-8f06a7374b81

Conflicts:

	app/models/auth_source_ldap.rb
	test/unit/auth_source_ldap_test.rb

Conflicts:

	app/models/auth_source_ldap.rb
	config/locales/en.yml
	test/unit/auth_source_ldap_test.rb

[#733] Add Issue#due_today? and add due-today css class

Contributed by Peer Allan