Add GNU General Public License v3

fixed crashing while changing map

path_sync app compiling and running

modified logger to support logging in files

modified logger to enable logging in file.

THE APP IS NOW COMPILING.

added app dir

added path_sync_core library, its now compiling

changed implementation of Scene and Map

CellType is an enum class now

added solver_type in solver_interface

added test files for astar_joint_state_utils

added test folder

renaming psync --> path_sync

added astar_joint_state implementation file