Created base for wrapper singleton class NetworkAccessManager
Switched Agent to NetworkAccessManager
Switched AudioMixer to NetworkAccessManager
Switched Application to NetworkAccessManager
Switched BillboardOverlay to NetworkAccessManaqer
Switched AvatarData to NetworkAccessManager
Switched AccountManager to NetworkAccessManager
Switched DomainServer to NetworkAccessManager
Switch ImageOverlay to NetworkAccessManager
Switch ModelUploader to NetworkAccessManager
Switch ModelsBrowser to NetworkAccessManager
Switched ResourceCache to NetworkAccessManager
Switched ScriptModel to NetworkAccessManager
Switched ScriptEditorWidget to NetworkAccessManager
Switched SnapshotShareDialog to NetworkAccessManager
Switched ScriptEngine to NetworkAccessManager
Switched XMLHttpRequestClass to NetworkAccessManager
Switched Sound to NetworkAccessManager
Added thread safe implementation of NetworkAccessManager main methods
Merge branch 'master' of https://github.com/highfidelity/hifi into replace_qnetworkaccessmanager