Improve conventions usage in the examples and add comments

[purbon]

Hi,
in this PR I tried to:

• Apply all recommendations by @enebo about class naming and conventions usage ([WiP] Add a simple example for basic/common things done in extensions #2 (comment))
• Added another method to show more options for static methods
• Added comments and clarifications ( I hope ) in the source code, so readers might get more an idea of what happened.

(disclaimer: I'm not sure why git delete&create a new file when doing the Foo -> RubyFoo rename, I apologies for the inconvenience).

Relates to #1

[rtyler]

teh -> the

[mkristian]

not sure if this is the right spot to put my 2 cents to it:

https://github.com/jruby/jruby-examples/blob/master/extensions/basic/lib/basic.rb#L4

is a very expensive feature of the LoadService since it means on each not found it looks on the classloader to a find class with a specific name, since the require can have an absolute file name it needs to do linear search of names.

requiring a jar does trigger the classname search. currently the classnames search even happens once before loading the jar (https://github.com/jruby/jruby/blob/master/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java#L73) and then again after the jar file is added to the classloader (https://github.com/jruby/jruby/blob/master/core/src/main/java/org/jruby/runtime/load/LibrarySearcher.java#L313).

IMO declaring an extension more the java way like jruby/jruby#2987 and not searching for a java class on any missed require will improve the LoadService. rubygems does its activation of gems also on missed required as well - so our missed require might not a miss after rubygems did its job.

[kares]

seems like this is out of date for the time being ... maybe at this point its best closed?

[monkstone]

I agree, plus it would be a wasted effort to resolve conflicts