Fixed VS crash due to unability to parse thread-id

Sometimes, for some reason GDB returns thread-id as '??' instead of number.
Refactored MSBuild tasks
Fixed GdbHost.exe expected location for debugging

For VS2010 - referencing native assembly behaves differently than in VS2012 & VS2013.
The path to GdbHost.exe is different then.
Unified flag files management

Fixed the way -debug-native & CSK-passwords are passed from Visual Studio
to MSBuild. The idea is to use files in project's folder, automatically
deleted, when build/deployment is done.

This commit also fixes non-working debug-native flag, so it is possible now to
put and stop on GDB breakpoint inside the first line of main() method for desired application.

CSK-password is used to pass a CSK certyficate key used during BAR signing
process (in case someone doesn't want to store it persistenlty in system registry).
Disabling IntelliSense errors reporting

When BlackBerry project is open, since we currently didn't alter it to
understood Qt extended C++ syntax etc. It could then make most of the code
red highlighted.
Fixed unnecessary asking for binary location

When Cascades application built in Device-Release mode was simply run
without debugger attached.
Added XSD for bar-descriptor.xml
Updated all projects with new bar-descriptor XSD

Now the code can be easily re-created using xsd.exe tool.
All custom code was placed in bar-descriptor.Extensions.cs

Still current solution suffers from previous problems:
 * comments are removed on bar-descriptor.xml save
 * fields order is enforced
Imporved IntelliSense disable tracking
Made default name of Headless App shorter

As it could cause some compilation issues due to too long entry-point-id.
Added entry-point support in bar-descriptor.xsd