multiple target and multiple targetnames per entity support

original code and concept by ==Troy==, rewritten by /dev/humancontroller
ported c1c289d, 6018f9b and cb52adc to unvanquished by Tim
adapt function and variable naming and add some documentation
Port client logging from Tremfusion.
daemonmap->Q3MAP2; +func_group; general cleanup
Merge branches 'master' and 'feature/multitarget' into entities
add target_relay to entity def and update all already ported entitiesdefs to reflect multitarget and multitargetname functionality