Optimize string operations

This removes the excessive splitting and string replacement with proper
splitters. We also add better length/range constraint validation.

Change-Id: Ia69d29a307cc23b22bf282ed17e9f585a41ae336
Signed-off-by: Robert Varga <rovarga@cisco.com>
Eliminate use of String.split()

Another round of optimizations, centered about not instantiating
implicit pattern matchers, but rather using Splitters.

Change-Id: I9ebba19fd9f211e7fa55e9bb55e35ae5e2a7b379
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-865: eliminate the use of YangTypesConverter

Uses BaseTypes instead.

Change-Id: I7c1f71f986813872a5680147e87c800f9764b868
Signed-off-by: Robert Varga <rovarga@cisco.com>
Optimize ParserListenerUtils()

- instanceof check implies null check
- use direct return instead of a break when returning things

Change-Id: Ibcd9198a3505da72d2abb90ce348f2ddf2e1e35b
Signed-off-by: Robert Varga <rovarga@cisco.com>