CRM-14798 - CaseType - Make "name" handling simpler and more intuitive

Prior to v4.5, the naming for a case-type flowed more or less like:

 * The admin makes up a display-name (title/label -- eg "Housing Support")
 * That title is automatically munged via CRM_Utils_String::titleToVar to produce a machine-name (eg "Housing Support" => "housing_support")
 * That machine-name is munged via CRM_Case_XMLProcessor::mungeCaseType to produce a file-name (eg "housing_support" => "HousingSupport.xml")
 * The admin goes back to rename his file to match the double-munged version.

With this patch, the mungeCaseType() is deprecated. Instead, the
machine-name may be set manually or automatically, and the file name should
match the machine-name.  If it doesn't, then a warning will be displayed
through CRM_Utils_Check.

(Replaces https://github.com/civicrm/civicrm-core/pull/3578 )