append the .rb extension on Cask::Source::Path

Unless `.rb` is already present on the query string.  Failure
to append the extension caused confusing effects, including
selective failure of "brew cask list" when invoked from
`/usr/local/bin` working directory.  Fixes #4077 .
Credit to @mroth on the detective work.
Clarified when to use certain options

Options such as '--caskroom' and '--appdir' should be used in
conjuntcion with 'brew cask install'.

Addresses #3813.
flash: 13.0.0.214 update

flash: 13.0.0.214 update
Update VyprVPN to version 2.3.3.1851
Merge pull request #4377 from txase/update_vyprvpn

Update VyprVPN to version 2.3.3.1851
quoting and pathnames on `chmod` command
quoting and pathnames on `chmod` command
Merge pull request #4365 from vitorgalvao/clarify-usage-options

Clarified when to use certain options
updated shotcut (140502)
Merge pull request #4381 from vitorgalvao/update-shotcut

updated shotcut (140502)
Merge pull request #4360 from rolandwalker/extension_on_cask_source_path

append the .rb extension on Cask::Source::Path
updated scala-ide (3.0.3)
updated iannix (0.9.16)
updated chainsaw (latest)
Add SQLiteStudio 2.1.5.
updated id3-editor (1.21.25)
updated ltspice (4)
updated navicat-for-mariadb (11.0.17)
updated navicat-for-mysql (11.0.17)
updated navicat-for-oracle (11.0.17)