Added debug flag
respect debug flag in builder
only use RoslynInMemory engine with debug flag
module loader should look into current directory if running in debug mode
Debug flag should have default value
Merge branch 'dev' of https://github.com/scriptcs/scriptcs into friendly-module-loader
fixed breaking tests
automatically set loglevel to debug if -debug flag is found
Merge branch 'dev' of https://github.com/scriptcs/scriptcs into friendly-module-loader

Conflicts:
	test/ScriptCs.Tests/ArgumentParserTests.cs
Merge pull request #537 from filipw/friendly-module-loader

Added debug flag, allow easier module development

Fixes #473
Fixes #503