Change bash shebang to use /usr/bin/env.

That makes those scripts usable on systems where GNU bash is not in
/bin/.  E.g., NixOS.
Merge pull request #1905 from iqbalansari/master

Use 'path-separator' for splitting/joining environment variables
add recipe: add ac-js2 recipe
Added dash and s as dependencies for ag.
Merge pull request #1906 from ripple0328/master

add recipe: add ac-js2 recipe
Merge pull request #1907 from Wolfy87/feature/ag-dependencies

Added dash and s as dependencies for ag.
Update obsolete org-trello recipe
consider recipes with :checksum as "secure"

If the package recipe has a :checksum property no more work is needed:
either the checksum matches in which case we have a trusted version of
the package, or it fails to match (or doesn't have a :compute-checksum
method) so we get an error raised on el-get-post-install.

* el-get-methods.el (el-get-insecure-check): don't raise error if
  package recipe has :checksum property.
Merge pull request #1865 from ruediger/envbash

Change bash shebang to use /usr/bin/env.