#25 Integrate a version of LSLint into LSL-Editor core.

[Ima Mechanique]

Add LSLint as a core part of LSL-Editor (not just a plug-in) and enable as default syntax-checker.
LSLint is a much better checker of LSL's quirks (i.e. no string concatenation in globals, etc.) than it is possible with current conversion to C#. Creating a complete LSL compliant syntax checker in C# would be a very large undertaking and wasted effort, when such a good checker is available already.