Added namespace to occurences of symbol `features'

Built-in symbol `features', most often reliant for information of present capabilities of emacs runtime, was being shadowed by local dynamic binding, under the scope of a few routines. 

Resultant changes were determined after a simple grep search and dismissing those occurrences which were part of another symbol, a string or a comment. 

Although no thorough examination of context of affected code has been made, building procedure does not indicate any downfalls which set of automated tests would be able to determine.