Adding two new configuration options into hotswap-agent-core

[lancethomps]

-excludedClassLoaderPatterns: Comma separated list of class loaders to exclude from initialization, in the form of RegEx patterns.
-reloadCallback: Optional method to call (that can exist outside of Hotswap, ie in your own project) every time a class is reloaded.

[skybber]

Hi, first of all thanks for contribution! I would have some notes to your pull request:

• excludedClassLoaderPatterns is quite OK, it seem there is really missing such mechanism in HA and would be helpful in some cases.
• reloadCallback can be implemented simply in a plugin as custom solution. We prefer to keep the core minimalistic, therefore it can't be accepted.

Could you please change the PR by removing the reloadCallback? Thanks!

[lancethomps]

Removed reloadCallback.