[MP] Add the extra error messages to legacy game dll loading.
[MP] Fix NET_AdrToString to display port correctly.
Minor cleanup to NET_StringToAdr.
Use NET_AdrToString in a few places.
[MP] Fix name filtering to allow extended ASCII but not control characters, without chopping off valid characters
[MP] Also filter blank characters in names
Merge branch 'master' of https://github.com/JACoders/OpenJK