Merge pull request #110 from p0nce/master

Nicer <Folder> structure for combined VisualD project files.
Only update packages once per update call.
For the DependencyGraph, when dependencies are looked up, provide the base package name, to the callback.
A better log message in case of installing a package over a previous installed package and a bug fix, when the install .zip file is not containing any folders.
Improve wording of command line structure on the help screen.
Merge branch 'master' of github.com:rejectedsoftware/dub
Fix determining the zip root folder.
Always upgrade branch based packages for now.

Later on, the actual HEAD revision should be compared to what is already installed, so that upgrading is only done if necessary.
Don't exclude application file in the auto-inferred "library" configuration if the target type is explicitly set to library. Fixes #105.
Parse configurations after all global settings have been parsed. Fixes #113.
Only allow zip file prefixes of one directory deep. Partial fix for #118.
Only upgrade branch packages if required and never upgrade the same package twice. Fixes #118.
Update change log.
Fixed two small typos in Usage ouput.

Fixed a couple of small typos in the DUB usage message.
Merge pull request #121 from craig-dillabaugh/patch-1

Fixed two small typos in Usage ouput.
Use BuildOptions instead of DFlags to handle --debug=XXX flags on the DUB command line.
Change BuildOptions.init from "debug_" to the new "none" to fix bogus -debug flags during compilation.

Also fix formatting and enable the warning about using --debug=xxx compiled flags directly.
Improve log messages.
Fix typo. See #122.
Moved Journal into packagemanager.d. Removed Project.writeMetadata as it is not used. Documentation typos and updates.