Revisit the "assert" routine in the JNI part

[atanasovg]

At many places within the C++ code we use either the native assert or the ASSERT_XXX macro. We need to revisit the implementation like so:

• Use the C++ assert, which is disabled for release builds
• Use conditional error handling when the Runtime needs to fail and go with the ErrorActivity routine - that is, to pass the control back to Java via the NativeScriptRuntime::AppFail method.

Refers to #180 & #196

[tailsu]

This issue breaks https://github.com/chaijs/chai/blob/master/chai.js
The relevant part is:

            /*!
             * Buffer.isBuffer browser shim
             */
            var Buffer;
            try {
                Buffer = require('buffer').Buffer;
            } catch (ex) {
                Buffer = {};
                Buffer.isBuffer = function() {
                    return false;
                }
            }

Instead of entering the catch, the runtime crashes with F/TNS.Native( 4655): require should be called with string parameter.

[slavchev]

Another one reported by @tailsu

JNI DETECTED ERROR IN APPLICATION: JNI NewString called with pending exception 'com.tns.NativeScriptException' thrown in unknown throw location
try { require(...) } catch(e) {} where it throws SyntaxError

In short, the app crashes if it cannot compile the module JavaScript; it should not