layout.xml is static file, so it's safe to load it from resource.
In the same time, if layout.xml is changed like it happened after v2.6,
this way doesn't introduce problems with loading incorrect layout.
Incorrect layout was loaded incorrectly if v2.6 is installed through
package manager and we run locally compiled / installed exe.
FIXED: [ 386314 ] Install to a custom location doesn't work correctly