Merge pull request #14 from Handison/master

Added speed_control_code (tested)
added comments to explain mathematical derivation for encoder speed calculations
Merge pull request #15 from lintangsutawika/master

added comments to explain mathematical derivation for encoder speed calc...
ignore build, devel dirs
remove build/ and devel/
initializing navigation code
Merge pull request #18 from tttor/nav

Nav Init
Merge remote-tracking branch 'upstream/master'

Conflicts:
	robot/main/slave.cc