Silp

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Add support for YML launguage

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Fix the wrong `import silp` in setup.py which breaks the dependencies installation.

- https://github.com/yjpark/silp/issues/1
- Thanks for lowks for the comment: https://github.com/lowks

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--clean
Add `--clean` parameter to remove silp generated lines, usefel if want
to change the language settings

include other files in template
The syntax is something like:

<<[fish/fish.freshrc]

This is following the Marked (a markdown preview app on OS X) rule, so Marked
can show the included file content just fine.

freshrc support
freshshell is a very nice tool to manage dotfiles, though it doesn't support
include other freshrc at the moment(2014-05-06), so I split my freshrc into
smaller files, and use silp to put them into the main file.
- https://github.com/freshshell/fresh

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- Bugfix with the .md files not included in Manifest

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- Change name to "Simple Individual Line Preprocessor"

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- Better control with the padding spaces to keep all `generated_surfix` aligned
- Skipping files that not using SILP, to prevent the useless files in `.silp_backup`
and `.silp_test` folders
- Can support multiple project setting files with different extentions
- If a subfolder has it's own setting files, won't include them in the parant's `--all` run