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.
CentOS 5.10: Remove DHCP leases in clean up script
Merge pull request #890 from gzurowski/CentOS-5.10-Improvements

CentOS 5.10: Remove DHCP leases in clean up script
Use debian redirector to receive better mirrors
Merge pull request #891 from DavidS/use-debian-redirector

Use debian redirector to receive better mirrors
SSH connection test now works if it can connect even without receiving the existing connection error. tcp_test_ssh now checks the return from the second socket.connect_nonblock and will return true if that connection attempt was successful.
fix undefined local variable,definition_dir

Specifying an non writeable definition dir returned an undefined variable error rather than the helpful error message.
Running unnecessary media check every time

Skips to Install Fedora 20
from default
Test this media & install Fedora 20
Merge pull request #892 from ejsarge/master

SSH connection test now works if it can connect even without receiving the existing connection error.
Merge pull request #893 from braddeicide/master

Enable "DefinitionDir not writable" error msg, skip Fedora 20 media check.
FreeBSD-10: Reduce box size
Small tweaks
Create pkg.conf from the sample conf file

The puppet module for pkgng complains otherwise.
Merge pull request #894 from sc68cal/freebsd_10_shrink

FreeBSD-10: Reduce box size
Explicitly use authentication methods for Net::SSH.start().

Otherwise, Net::SSH.start() will *not* try password authentication if
a ssh key is available.

This solves issue #767.
Merge pull request #895 from htgoebel/master

Explicitly use authentication methods for Net::SSH.start().
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