More work on #854: Issues with having both debug and release modules in the same directory
Swapping debug/release plugin prefix
Simplify function::target_type() for empty functions
Adding closed tickets to docs
Preprocessed files
Avoid reloading a library if the symbol is not found

Signed-off-by: K-ballo <k@fusionfenix.com>
Merge branch 'master' of https://github.com/STEllAR-GROUP/hpx