Add EXCLUDE_METHODS

[kuzuk]

Add an environment option 'EXCLUDE_METHODS' that lists method names that should not be instrumented.

Use-case: small utility methods such as toString, equals, compareTo and hashCode should probably not be instrumented because they fulfill a technical rather than a logical role. Also, they are often called so often that logging or other usages of the instrumentation will degenerate. The performance will also suffer considerably for little or no gain.

The default of EXCLUDE_METHODS should be "toString, equals, compareTo, hashCode"