Compilation of plugins with debug information

As of 138a4115a6cfa21b5a776f70cc2c49d671189846, there's a new checkbox to enable plugin debugging in Procon's settings. Upon connecting to a gameserver, Procon checks whether plugin debugging is enabled. If so, it creates a new directory for the temporary files (the temp directory is emptied at every connection to prevent files from piling up) and toggles the needed settings in the CodeDom compiler. Plugins are then compiled with debug information and the PDB- and temporary files are kept. Furthermore, plugins are force-recompiled (ignoring the cache) if debugging is enabled.