compileMustacheDir Compile all templates in the specified directory and select one.
Template files should have the extension mustache, (e.g.
foo.mustache) to be recognized. This function does not scan the
directory recursively.
Note that each template/partial will get an identifier which consists of
the name of corresponding template file with extension .mustache
dropped. This is important for e.g. selecting active template after
loading (the first argument).
The action can throw MustacheParserException and the same exceptions as getDirectoryContents, and readFile.
compileMustacheDir = complieMustacheDir' isMustacheFile