Added convenience functions

Simplified repetative OJB exports by adding a function that combines obj
parsing and exporting while still supporting all existing features.
Made static
Added simple alpha mapping
Merge pull request #343 from Davhed/simple-alphamap

Added simple alpha mapping
Merge pull request #344 from ToxicBakery/master

Continuation of issue #335, fixed the remaining for-each instances and turned them into regular for loops.
Added uLightColor component
Added lights to diffuse
Made diffuse equations similar to phong

The PhongMaterial has the correct equations for ambient and diffuse. I
translated them to DiffuseMaterial.
Merge pull request #339 from Davhed/simplified-obj-export

Added OBJ serializing convenience functions
Updated Diffuse and Toon

Put "intensity" back into Diffuse and passed light color into
ToonMaterial. Still needs more testing with RajawaliExamples
Removed duplicate multiplication

Intensity was being multipied twice, this commit repairs that.
Fixed typos in DiffuseMaterial

"intenstiy" was spelled incorrectly in one case, and I also removed a
trailing ")".

Fully tested with Rajawali examples.
Updated PhongMaterial

Phong was not working properly with "use color". The float var
"intensity" has been added to capture LightPower, and is multiplied with
Kd within the sahder now.
Updated Bumpmap materials with uLightColor

Extended light color support to bumpmap materials
Updated equation for Kd

Intensity is once again an independent variable. I have multiplied
uLightColor(i) with the equivalent of intensity(i) to derive Kd which is
added to itself on each loop iteration. Kd * textureColor (or vertx
color) then completes the color calculation.
Merge pull request #345 from Davhed/utilize-lighting

Modified base materials to utilize uLightColor
Reduced number of calculation
Created an STL Parser for ASCII and Binary STL types. Parser auto detects STL type so it should work as a fire and forget style parser. In my tests I used various models from Thingiverse and did not run into any issues though I am sure some exist.

I am working towards further developments on this such as wireframe option and more testing.
Fixed two bugs.
1) In AMeshParser mRootObject is automatically instantiated by one constructor and not by the other.
2) StlParser assumed fileIn would not be null. This is not the case when loading from the SdCard.
Merge pull request #350 from Davhed/utilize-lighting

Reduced number of calculation