Use local todo.txt for project specific task lists

[jammon]

I tend to have rather long task lists for single projects filling up my global todo.txt. Although I can tag them with "@my_project" I don't like the confusingly long task list.

So I extracted the project specific task into local todo.txt files, that I can add to the project's git repo. This change to todo.sh makes it search up the directory path for a local todo.txt and use this if it finds any. The default behaviour is unchanged (not looking for local todo.txt), but you can turn on using local task lists with -l or TODOTXT_USE_LOCAL=1.

[AlexandreRoba]

Works like a charm. Lost an hour trying to play with TODO_DIR, TODO_FILE... on mac os and zsh and could not sort it out. IMHO This is a good candidate as default behavior.

[karbassi]

@jammon or @inkarkat, could one of you two write some test for this. I know others would love this feature merged.