added virtualbox provider quickstart
silkysun comments`s addressed
Update providers for 1.6. Consolidate providers/APIs onto one page.
updated release notes
doc updates for 1.5.7
Merge pull request #98 from rackspace/provider-cleanup-for-1.6

Update providers for 1.6. Consolidate providers/APIs onto one page.
Merge pull request #97 from andreaturli/master

virtualbox README updated
Merge pull request #103 from jclouds/1.5.7

doc updates for 1.5.7
Added QCon Guava presentation link
An OpenStack Swift example.
output broke parsing
Updated chef bootstrap methods
Merge pull request #99 from rackspace/openstack-swift-example

An OpenStack Swift example.
Merge pull request #104 from jdaggett/feature/guava-addition

Added QCon Guava presentation link
Merge pull request #106 from nacx/chef-bootstrap

Updated chef bootstrap methods
GitHub Pages didn't like back ticks for code formatting. Switched to pre.
Merge pull request #107 from rackspace/swift-example-format-fix

GitHub Pages didn't like back ticks for code formatting. Switched to pre.
Clarify that a BlobStoreContext should be reused and is thread-safe
Adding release notes for 1.5.4 to 1.5.7 to the overview page
Merge pull request #108 from benmccann/docs

Clarify that a BlobStoreContext should be reused and is thread-safe