Fix compiling under Android Studio

[dottools]

This PR fixes building and running under current Android Studio IDE stable release along with current Gradle build system.

Important Highlights:

• Changed APP_STL to c++_static as stlport_static is depreciated and broken in latest NDK anyway.
• Current compiler has RTTI disabled by default so C++ compiler flags updated to explicitly enable RTTI.
• Minimum SDK version changed from 16 -> 19.
• Minimum build tools is now 26.0.2 as required for current Android SDK.
• Torque's strstr variant wasn't standard library compliant and has been fixed for all platforms that Torque 2D compiles for and runs on. Was explicitly corrected for Android Studio because current compiler refuses to allow old/incorrect usages.
• All Android platform build specific warnings have been fixed.

[greenfire27]

Awesome! Thanks for doing this.