[ehcache26] DO NOT MERGE: Fixes to make it transactional
Create the plugin ff2

  * With support in RadarGunDataGridConfig to override FF defaults, such as
    hazelcast config.
[ff2] minor fixes to log exceptions
Create jvstm1 plugin (STM lock-based) (1 node only)
Create jvstm2 plugin (STM-lock-free) (1 node only)
Create the plugin ff2-lf

   * Similar to plugin ff2, except that it uses a lock-free commit algorithm
     extended from JVSTM.
   * With support in RadarGunDataGridConfig to override FF defaults, such as
     hazelcast config.
[ff2-lf] Use putIfAbsent when possible (Wrapper implements AtomicOperationsCapable)
[ff2-lf] minor fixes to log exceptions and optimize with putIfAbsent
DO NOT PUSH: my-stuff (confs, stats, benchmarks, bins)
more my-stuff to fixup
[framework] DO NOT MERGE: Update StressTestStage to account for read-only transactions

  * New property writeTxPercentage that configures "The frequency of
    transactions that may perform writes (percentage)".