Changes

Scripts: Bump to java 1.8.0_20

Bug 1017 - TextureIO.write(Texture, File) throws GLException Not a GL2 implementation on GL3 contexts

_gl.getGL2() -> _gl.getGL2GL3()

Bug 1052 - OpenGL ES 3.0 Mesa 10.1.3 Caught GLException: Not a GL4ES3 implementation - Part 1/2

Test enhancements triggering issue 'Bug 1052 - OpenGL ES 3.0 Mesa 10.1.3 Caught GLException: Not a GL4ES3 implementation'

- TestGLProfile01NEWT: Complete GLProfile and GL-object and GLContext validation

- On OpenGL ES 3.0 Mesa 10.1.4 it produces:

1) test06GLProfileGL4ES3(com.jogamp.opengl.test.junit.jogl.acore.TestGLProfile01NEWT)
javax.media.opengl.GLException: GL4ES3 is neither GL4bc, GL4 nor GLES3
    at com.jogamp.opengl.test.junit.jogl.acore.TestGLProfile01NEWT.validateGLProfileGL4ES3(TestGLProfile01NEWT.java:531)
    at com.jogamp.opengl.test.junit.jogl.acore.TestGLProfile01NEWT.validateOffline(TestGLProfile01NEWT.java:708)
    at com.jogamp.opengl.test.junit.jogl.acore.TestGLProfile01NEWT.test06GLProfileGL4ES3(TestGLProfile01NEWT.java:948)

i.e. wrong mapping of request GL4ES3 -> GL3

Bug 1052 - OpenGL ES 3.0 Mesa 10.1.3 Caught GLException: Not a GL4ES3 implementation - Part 2/2

- TestGLProfile01NEWT: Allow ctx.isGLES3Compatible() and hence GL4ES3 on GL3bc and GL3

- GLProfile: Remove GL4ES3 mapping using GL3bc and GL3, only GL4bc, GL4 and GLES3 are allowed in static mapping.

GLProfile: Use String.intern() on static final profile strings ('GL4bc', 'GL4', ..) consequently using reference comparison.

GLProfile already compared profile strings by reference, hence interning those strings
to become canonical references was missing!

Consequently using reference comparison for all profile strings in GLProfile.

Bug 1048: Add unit tests demonstrating multiple NewtCanvasAWT instances are working

Enhance following performance test cases, adding NewtCanvasAWT,
beside GLCanvas and GLJPanel, 25 instances:
  com.jogamp.opengl.test.junit.jogl.perf.TestPerf001GLJPanelInit01AWT
  com.jogamp.opengl.test.junit.jogl.perf.TestPerf001GLJPanelInit02AWT

Adding simple com.jogamp.opengl.test.junit.newt.TestMultipleNewtCanvasAWT
w/ two instances.

Manually tested on GNU/Linux and OSX (java7 and java8).

Bug1044: Offscreen drawable AWT/ImageIO results in black image on OSX/[Java7-Java8]

- Using our PNGJ writer results in proper images (RGB and RGBA) on all platforms
- Seems to be a bug w/ AWT/ImageIO

Bug 1043 - Add Tessellation Control and Evaluation Shader Support

- Add GL4.GL_TESS_CONTROL_SHADER and GL4.GL_TESS_EVALUATION_SHADER support for GLSL util class ShaderCode
- Add unit test TestTessellationShader01GL4NEWT, testing TessellationShader01aGL4 and TessellationShader01bGL4

Bug 1058 - Fix GLContext.getGLSLVersionString(): Add 'profile' after version for GLSL >= 150 allowing GLSL compatibility profile

HowToBuild: Debian i386 on x64: Add symbolic links for shared libs

Bug 1059 _and_ version-compat breackage of commit c78ceb642d0ef5bb5bf27ff8ff1495175ee2e983

Commit c78ceb642d0ef5bb5bf27ff8ff1495175ee2e983 changed:
  -    public static final String GL4   = "GL4";
  +    public static final String GL4   = "GL4".intern();

which is identified by semver as incompatible,
due to Bug 1059 (no more inlining of interned string references).

Adding missing '@since 2.2.1' tags to ShaderCode and GLContext

Bug 1060 - Add GLProfile.isInitialized(): Returns true if JOGL has been initialized

Bug 1047 - jogamp.opengl.glu.mipmap.Mipmap now uses already parsed GL version number and GL profile selection

Since Bug 1047 didn't provide a unit tests, this must be fine for now.

LICENSE.txt: Emphasice incompatible A.7) module is OPTIONAL