Properly delete arrays.
Added missing method chaining to framebuffer configuration functions.
Introductory documentation about method chaining.
TextureTools: initial rude implementation of distance field computation.

Not yet ported anywhere else than GL >= 3.3 with some GL 4.3 features.
Still, this closes #3.
TextureTools: proper function name in assert.
A little bit of const fascism.
TextureTools: support padding in atlas().
Text: minor code cleanup.
Text: prerendering Font for use with distance-field rendering.

Currently there is no builtin shader capable of it, will come later.
Shortened (texture) filtering types to comply with OpenGL naming.

The documentation already used them, so why complicate things further.
Todo++
Shaders: renamed TextShader to VectorShader.

The code can be used for drawing any vector art, not only font glyphs.
Shaders: vertex VectorShader is implementation independent.

Renamed it to AbstractVectorShader.
Shaders: support alpha in VectorShader::setColor().
Shaders: cleanup of VectorShader.

Using this-> for accessing parent class members breaks KDevelop
autocompletion, using explicit class name instead (but the shorter one).
Shaders: use Int instead of GLint.

Don't know how this only place got forgotten.
Shaders: missing virtual keyword.

This was compiling?! It seems that I don't know more than I think.
Shaders: doc++
Shaders: first DistanceFieldVectorShader implementation.

Currently only fill and outline can be specified. Also crosslinked from
documentation of VectorShader and TextureTools::distanceField().
Text: synchronized function parameter naming with documentation.