Shrimp Shader Generator FLTK2 GUI (SVN)

Tweaked fractal headers, it's more useful to have lacunarity, gain, and offset on fBm, Ridged, VLfBm, Turbulence, as varying storage, rather than uniform.
Changed the respective blocks as well.

Continued to clean the blocks, adding more meaningful names for inputs and outputs for the GUI. Moved dPdu and dPdv from Derivatives menu to the Inputs menu since they're global variables.

Tweaked more blocks, adding more meaningful names to improve usability in GUI.

update connection in progress with using stipple spline

Continued to tweak the block's input and output pad names, so that readability is improved in the main window.

FIX: zoom slider wasn't clamped properly

Leave original active>mousepointer (straight) connection line, and commented active>mousepointer spline code - it's there for reference only.

Further tweaks to GUI, rolled up blocks color is consistent with UI theme, width/height ratio for blocks is tweaked (thanks Ben).

Added Ben's spline curve connection lines. Stippled origin>mouse position splines aren't working yet. Width/height ratio changed as well.

Made input pad text (on blocks) scale dependent, now font size scales with zoom level.