Avlwrapper

- Support multiple cases in 1 input file
- Added body forces output
! - Cases are now indexed by number instead of name, since names are not required to be unique

- Lots of bugfixes:
- Creating Body while parsing inputfiles
- RegEx bug in ElementFileReader (Thomas Greenhill)
- Handling large numbers in tables
- Handling stripforces with index > 99
- Missing values now replaced with NaN instead of messing up the table format
(columns were incorrectly shifted in previous versions)
- Name labels incorrectly read in SurfaceFileReader
- Type errors (mixing up floats & ints) while reading and writing files
(AVL usually handles correcntly, but huge gain for consistency)
- Case can now be read from input file
- Spacing now parsed correctly
- Two Spacials can now be added
- Spacial can be multiplied/divived with a number
- Added _underscore to separate control name from derivative (CYuelevator => CYu_elevator)
- Added tests cases

- Bugfix for AIRFOIL keyword

- Merged bufixes from Dario Isola & Phil Chiu

- New Model class
- AVLWrapper can now read an AVL input-file

- Configuration is now settable during runtime