Include common Troubleshooting issues section and Windows7 issue

[laurencei]

There seems to be a number of 'common' troubleshooting issues with Homestead that people need already.

I've added a troubleshooting section (for future issues) - and included an issue for Windows 7 users that they might need.

See this forum thread for more info: http://laravel.io/forum/05-18-2014-trouble-getting-homestead-to-start-in-windows

[ComFreek]

The tool does not work on Windows 8 (it displays a message saying it only supports XP, Vista and 7).

The Intel® Processor Identification Utility works for me.

EDIT

Enabling VT-X in the BIOS is sometimes not enough. One has to deactivate the Hyper-V platform.

See:

• http://social.technet.microsoft.com/Forums/windows/en-US/0d4d01a3-3488-4edb-8eec-52de0ca0c496/intel-haxm-and-hyperv-are-they-mutually-exclusive?forum=w8itprovirt
• http://stackoverflow.com/questions/13285682/android-sdks-intel-haxm-disabled-after-installing-hyper-v

[taylorotwell]

Added note.

[ianchanning]

I hit this problem but didn't spot the note that's been added to point this out. It would make more sense if the note was moved to the section where you call vagrant up as that's when you hit this problem.