update CoC to 0.4

see https://github.com/Bantik/contributor_covenant
Create GDAL Framework 1.11 Cask
Required as dependency to install QGIS
See #5074
The complete framework package is installed because most applications that use GDAL will also need Proj, UnixImage and Numpy.
DSL add uninstall `:delete` and `:trash`

- `:delete` is intended to replace `:files`
- `:trash` is intended to move files to the OS X Trash
- `:trash` is only a stub — currently all three function identically

References: #4688
move read_script_argument to Cask::Artifact::Base
generalize read_script_arguments

so that it can be called from multiple stanzas
harmonize error messages
read_script_arguments accepts defaults/overrides

as parameters.  Accept overridden keys when submitted by the
caller, but warn that they are ignored.
add luminance-hdr 2.4.0
install rspec; move first few tests over

refs #5080
Merge pull request #5120 from caskroom/install-rspec

install rspec; move first few tests over
Add Cask Xamarin, replacing older Xamarin Casks

These packages are: xamarin-android, xamarin-ios, and xamarin-studio.
They have been added to homebrew-versions.

Only call caveats once on Xamarin cask
rspecify scopes and download strategy tests

refs #5080
Merge pull request #5132 from caskroom/rspecify-part-1

rspecify scopes and download strategy tests
Merge pull request #5118 from fapper/xamarin

Add Cask Xamarin, replacing older Xamarin Casks
Merge pull request #5125 from jconley/luminance-hdr

add luminance-hdr 2.4.0
Seil 10.9.0
Merge pull request #5134 from NanoXD/seil

Seil 10.9.0
update CotEditor to 1.5.4
Merge pull request #5138 from vitorgalvao/fix-5137

update CotEditor to 1.5.4
Connector 2.2.3