Add --ignore-files to ignore a custom list of files in build, run, and lint

[kumar303]

#85 added some simple defaults for ignoring files when building an XPI. Let's support --ignore-files that the developer can use to declare custom rules.

See #176 for general config file support which will allow developers to configure this option.

[kumar303]

Let's do the general config file logic first: #176

[kumar303]

This seems pretty important. It looks like some people are putting sign.sh (which includes API keys) in the root of their project. This will get included in an XPI by default.

[lidel]

I have use case that would greatly benefit from adding --ignore-filenames=*.zip,*.foo parameter to both build and lint.

The add-on I am building relies on "browserified" and "minimized" NPM libraries which need to be included during build, but produce a lot of warnings when I run lint.
Due to this I often just ignore lint output -- too noisy to analyze every time.

Excluding these 3rd party artifacts from lint would improve the situation, as I could focus on removing any warnings from the code I control.

[kumar303]

Note to self: when we document this we should link to this cheat sheet for how glob patterns work: https://github.com/isaacs/node-glob#glob-primer

[rpl]

@kumar303 additional note: when we document this we should mention that glob patterns (e.g. like "node_modules/**") needs to be quoted to prevent the shell to expand the glob pattern into the entire list of files that verify the glob pattern.

[kumar303]

Here is the documentation. @rpl or anyone, let me know if anything is unclear or needs tweaks: https://developer.mozilla.org/en-US/Add-ons/WebExtensions/web-ext_command_reference?document_saved=true#--ignore-files_-i

[kumar303]

or @eight04 too! ^