Fixed issues in package.xml and CMakeLists
Fix return of function to get rid of warning
Added function to generate datetime strings
Added function for directory creation
Added ransac function for finding lines, but has compilation issues

Tried to compile the segment_stitching package, making use of pclutil, but does
not seem to work, undefined references to some functions from the line model and
other pcl libraries. Not sure what the issue is yet.
Added an operator+ for the pcl::PointXYZ object
Added a prototype rotateCloud to be used by rotateLine in SegmentStitching
Removed old ransac code
Added function to convert PCL point to geometry_msgs point
Added occupancy grid utils submodule
Added function for rotating point around origin on XY plane
added geometry files to visionutil
fixed nonmatching function headers
Changed mathutil filenames for consistency, added line equation computation
Added maputil package for operations on OccupancyGrid
Added functions to maputil for getting indices of rectangles, lines on grid

Also fixed index retrieval based on float (x,y) points
Removed occupancy grid utils
Added function for rotating geometry_msgs::Point
Fixed bug in rotation code
Merge branch 'develop'