Merge pull request #1 from arpg/fix/visual-only-calibration

Fix/visual only calibration
Merge pull request #2 from arpg/fix/visual-only-calibration

Fix/visual only calibration
Avoid imu calibration if no -imu command given
Added option to save grid in an EPS file
use_grid_preset parameter removed, and default values given for models parameter
Fix: grid_size dimensions are consistent
Added a constant for no grid preset present
Merge pull request #3 from arpg/save-pattern

Option added to save grid in an EPS file
Pattern can be saved in SVG
Some crashes fixed and interface changed.
IMU is not calibrated if no -imu param is given (prevents crash).
Crash fixed at the end of a sequence when -cam log://.
Option changed: exit on finish true by default.
Option changed: poly3 distortion model used by default.
Option added: key '[' starts calibration.
Merge pull request #4 from arpg/feature/save-svg

Pattern can be saved in SVG
Merge pull request #5 from arpg/fix/crashes

Some crashes fixed and interface changed.
Adds command line option (true by default) to use system time.
Merge remote-tracking branch 'origin/master' into fix/visual-only-calibration