Added jsoncpp library.
Added existing install check.
Added common set up file, sourced from all existing shell scripts and moved base configuration block into common.
Moved count_files, get_relative_path and str_contains into common bash file. Also removed definitions of it from all other bash files.
Moved resolving of base dir back into setup files and use it as a prefix when finding setup_common.sh
jsoncpp is now sourced from a .tar.gz rather than a .zip
Merge pull request #20 from NASA-Tensegrity-Robotics-Toolkit/serialization

jsoncpp integration
Extracted package specific configuration from install.conf into package specific conf files.
Renamed install.conf to general.conf to reflect its new role.
Modified file description header to reflect new name and role.
Now ignoring all files of type conf in conf directory.
Refactored conf sourcing to support loading by file name.
Each package specific setup script now sources its package specific configuration.
Package configuration existence check (as well as creation) added.
Fixed calls to source_conf
Moved jsoncpp initialization ahead of bullet and boost so when boost gives an erroneous failure the next set up completes nearly instantly.
Extracted true/false constants into setup_common.sh
Added SHA1 hashing (for file integrity verification) configuration options.
Merge pull request #22 from NASA-Tensegrity-Robotics-Toolkit/setup_refactor

Setup refactor
Merge branch 'master' of https://github.com/NASA-Tensegrity-Robotics-Toolkit/NTRTsim into corde