Added server plugins support (plugins server asks client to use)
Changed plugin prompts, added plugin source notice
Download server-sent plugins as zip files and extract them, instead of just gml
incorporated MedO-suggested plugins code refactor
error if plugin list > 254 chars
validate plugin names and check for duplicates
Store temporary files in temp_directory not working_directory
Export 7za.exe to temporary directory instead of working directory
apply server-sent plugins to host, too
second half of that commit (oops)
file var -> pluginname var, simpler tempfile/dir handling
Merge branch 'master' into serverplugins
Simplified "plugins required" flag, some restructuring
Wir sind die Coding-Stil-Polizei. (also simplified extractzip)
Fetch server-plugins from local debug folder, if available
Merge pull request #104 from TazeTSchnitzel/serverplugins

Added server plugins support (plugins server asks client to use)