[Most of] variables quoted to allow multi-word warning messages, spaces in file/directory names, etc.
Added double quotes to paths in concat command, so that it does not fail when path of target file contains some blanks.
Merge pull request #150 from lweller/issue_149

added double quotes to paths in concat command
Merge pull request #121 from acca301/master

[Most of] variables quoted to allow multi-word warning messages, spaces ...