devscript: add `list_url_attributes_on_file`

Uses OS X extended attributes (via `xattr`) to find the source
of a downloaded file.
Merge pull request #4729 from rolandwalker/add_list_url_attributes_on_file

devscript: add `list_url_attributes_on_file`
Merge pull request #4733 from rolandwalker/helpdoc_cleanup

remove issues_url and nullcommand from help output
`collect_concat` is not available in Ruby 1.8

`collect` is fine here. References #4719.
plus bugfix: join into a string so that `render_with_none`
knows to substitute "<NONE>"
Merge pull request #4739 from rolandwalker/doctor_backward_compat

`collect_concat` is not available in Ruby 1.8
Separate the HTTPS statement under one heading

also update examples to use HTTPS
travis: add before_script stanza
Travis: explicit full paths from env matrix
set bundle --system
set gem --bindir
better group before_install vs install stanzas
add informational feedback during before_install
comments/whitespace
SourceTree 1.9.4
Merge pull request #4735 from rolandwalker/travis_multi_ruby

Travis multi-Ruby support
Merge pull request #4740 from ahbeng/sourcetree-1.9.4

SourceTree 1.9.4
Upgrade Android Studio.app to v0.6.0 build-135.1212210
add SogouInput
Merge pull request #4742 from pan-long/add-sogouinput-with-manual-installer

add SogouInput
Merge pull request #4741 from tolbkni/android-studio

Upgrade Android Studio.app to v0.6.0 build-135.1212210