Remove rel_path causes issues on windows across drives.

Given
	PWD is z:/src/gendev
	RUBY is installed in C:/Ruby193
	path1  = veewee/iso/sol-10-u11-ga-x86-dvd.iso
	path2  = Z:/src/gendev

When
	I run veewee vbox build <definition>
Then
	 I get the following error.

	C:/Ruby193/lib/ruby/1.9.1/pathname.rb:465:in `relative_path_from': different prefix: "" and "Z:/src/gendev" (ArgumentError)
	        from C:/Ruby193/lib/ruby/gems/1.9.1/gems/veewee-0.3.12/lib/veewee/provider/core/helper/iso.rb:116:in `verify_iso'
	        from C:/Ruby193/lib/ruby/gems/1.9.1/gems/veewee-0.3.12/lib/veewee/provider/core/box/build.rb:37:in `build'

Since both a relative and absolute paths should work with curl, md5, and shasum there should be a need to validate a relative path to the iso.
Add option '--skip-to-postinstall' to build command.

This will skip the installation and go streight to postinstall. It is
usefully for testing you post-install scripts without running throug
the whole, time-consuming install process.
Add documentation for option '--skip-to-postinstall'.
Do not try to start the box if it is already running.
Merge pull request #896 from htgoebel/shortcircuit-postinstall

Shortcircuit postinstall
Merge remote-tracking branch 'origin/master'

Conflicts:
	lib/veewee/provider/core/helper/iso.rb
Remove rel_path causes issues on windows across drives.

Given
	PWD is z:/src/gendev
	RUBY is installed in C:/Ruby193
	path1  = veewee/iso/sol-10-u11-ga-x86-dvd.iso
	path2  = Z:/src/gendev

When
	I run veewee vbox build <definition>
Then
	 I get the following error.

	C:/Ruby193/lib/ruby/1.9.1/pathname.rb:465:in `relative_path_from': different prefix: "" and "Z:/src/gendev" (ArgumentError)
	        from C:/Ruby193/lib/ruby/gems/1.9.1/gems/veewee-0.3.12/lib/veewee/provider/core/helper/iso.rb:116:in `verify_iso'
	        from C:/Ruby193/lib/ruby/gems/1.9.1/gems/veewee-0.3.12/lib/veewee/provider/core/box/build.rb:37:in `build'

Since both a relative and absolute paths should work with curl, md5, and shasum there should be a need to validate a relative path to the iso.
Merge remote-tracking branch 'dopry/master'
Merge pull request #855 from dopry/master

Fix windows breakage in relative_path resolution  in verify_iso.
Fix CentOS 5.9 templates with backports of version 5.10 templates

Due to numerous bugs in the templates and the relocation to the CentOS
vault, the previous CentOS 5.9 templates failed to create VM images.
This commit replaces the previous templates with backports of the CentOS
5.10 templates. All templates now point to vault locations for both ISO
images and package repositories.

Signed-off-by: Gregor Zurowski <gregor@zurowski.org>
Merge pull request #899 from gzurowski/Fix-CentOS-5.9

Fix CentOS 5.9 templates with backports of version 5.10 templates