[NEW]: added pure reference synthesizer
Merge branch 'maz-changes' into v3

* maz-changes:
  [NEW]: added pure reference synthesizer
Added Secure input for CCEditBox on Mac
[NEW]: Implemented NSSecureTextField when CCEditBox inputFlag is set to Password
[FIX]: Cleanup CCEditBoxMac. CCCustomNSTextField class is not needed.
Oops, removed CC_SYNTHESIZE_READONLY_PURE_REF, which is something I added for myself.
Merge pull request #6774 from Mazyod/v3-mac-secure-input

V3 mac secure input