Fixed property input for negative values
Fixed property input for negative values

zr_strtof did not have a conversion case for negative float values
which caused problems for negative float text input. In addition
zr_filter_decimal had a bug that did not allow '-' as correct input.
Both bugs have been fixed and it should work now.

OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/midi_matrix.lv2,glegris/nuklear4j,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/sherlock.lv2,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/midi_matrix.lv2,OpenMusicKontrollers/synthpod,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/moony.lv2,OpenMusicKontrollers/patchmatrix,OpenMusicKontrollers/midi_matrix.lv2,glegris/nuklear4j,OpenMusicKontrollers/moony.lv2