Loads a template file. If caching is on, then it checks whether a "prepared" template exists. If it does, it gets loaded instead of the original, if it does not, then the original gets loaded and prepared and then the prepared version is saved. addBlockfile() and replaceBlockfile() implement quite the same logic.
Parameter
string
$filename
filename
boolean
$removeUnknownVariables
remove unknown/unused variables?
boolean
$removeEmptyBlocks
remove empty blocks?
Return value
returnSIGMA_OK on success, error object on failure