Adding new grep tools

[tylerw]

What is the proper way to add custom greppers? Prior to e1a48d0 I was using this configuration:

let g:grepper = {
    \ 'tools': ['git', 'sift', 'ag', 'pt', 'ack', 'grep'],
    \ 'sift': {
    \   'grepprg': 'sift -i -n --no-color --no-group $* .',
    \   'grepformat': '%f:%l:%m',
    \   'escape':     '\+*^$()[].',
    \ }}

...and it worked as expected. After that commit (and b1c1904), I see the following when invoking Grepper:

grepper: Ignoring unknown key "sift".
Don't understand: sift

...and the following error when hitting <Tab> at the Grepper prompt:

##Error detected while processing function grepper#parse_command..<SNR>213_start..<SNR>213_prompt..<SNR>213_tool_escape..<SNR
>213_option:
line    5:
E716: Key not present in Dictionary: sift
E15: Invalid expression: s:options[s:options.tools[0]]
Error detected while processing function grepper#parse_command..<SNR>213_start..<SNR>213_prompt..<SNR>213_tool_escape:
line    4:
E715: Dictionary required
Error detected while processing function grepper#parse_command..<SNR>213_start..<SNR>213_prompt..<SNR>213_prompt..<SNR>213_option:
line    5:
E716: Key not present in Dictionary: sift
E15: Invalid expression: s:options[s:options.tools[0]]
Error detected while processing function grepper#parse_command..<SNR>213_start..<SNR>213_prompt:
line   20:
E171: Missing :endif
Error detected while processing function grepper#parse_command..<SNR>213_start:
line   14:
E171: Missing :endif

[mhinz]

Argh, silly mistake. Please pull again, it should work now.

[tylerw]

Yes, that did it, thanks!