Fix javadoc bug for java version prior to 8.

This option is unsuported with javadoc compiler prior to 8 and make the task failed.
Merge pull request #91 from KyuBlade/patch-1

Fix javadoc bug for java version prior to 8.
Marking entities about to be removed, avoiding multiple removal
Merge pull request #102 from Lusito/scheduled_for_removal

Marking entities about to be removed, avoiding multiple removal
Test exhibiting stack overflow when adding/remove entities.
Fixes #103: no more StackOverflowError.
removed another call to processPendingEntityOperations (thanks @Lusito)
Adding another EntityOperation RemoveAll. Fixes #101
Merge pull request #108 from Lusito/remove_all

Adding another EntityOperation RemoveAll. Fixes #101
Merge pull request #105 from junkdog/103-stackoverflow-entity-operations

stackoverflow entity operations