Merge branch 'terencehill/bot_fixes' into 'master'

Merge branch 'terencehill/bot_fixes' into 'master'

Bot fixes

* Make misc_breakablemodel entities secondary target for bots so they never prefer shooting at barrels over players
* While shooting at breakable objects, don't focus on them, be ready to choose another enemy
* Properly set bot_attack field in a few more situations (reset bot_attack field when going observer, and set/reset it properly when freezing/unfreezing somebody)

See merge request !197