Remove uninstll script & inlined __bd_usage function (fixed #16)

Fix typo in help, make modes more clear and add note about fuzzy matc…

…hing, closes #13

Merge pull request #12 from znculee/pr

Do not complete current folder

Write errors to stderr instead of stdout. Resolve #9

Merge branch 'master' of github.com:0rax/fish-bd