Finally started writing automated tests :-)
Bug fix based on tests: Don't add duplicate directory separators in xolox#misc#option#eval_tags()
Bug fix based on tests: Don't generate errors on empty paths in xolox#misc#path#join()
Move xolox#misc#timer#format_timespan() → xolox#misc#format#timestamp()
Reliable detection of xolox#misc#timer#start() return values
Add string coercion to xolox#misc#msg#info() & similar functions
Add xolox#misc#format#pluralize() function
Extract testing framework from test suite
Add xolox#misc#str#ucfirst() function
Improve xolox#misc#os#find_vim() function

Now accepts a 'vim' or 'gvim' argument to allow callers to
indicate their preference independently from 'v:progname'.