Change handlers->tasks in httpstack_utils.h
Rename HTTP Controllers->Handlers
Finish renaming HTTP Controllers->Handlers
Eliminate all controllers from http
Rename Diameter Handlers->Tasks
Rename Diameter Controllers->Handlers
Correct some naming errors in diameterstack.h
Correct fd_log_handler_register name
Correct fd_log_handler_unregister name
Correct Indenting
Markups
Merge pull request #153 from Metaswitch/Rename_Handler_Branch

[Reviewer: Alex - Do not merge] Rename handler branch