added async flag to all storages
DevNullStorage changed to DevNullSyncStorage
prepared DevNullAsyncStorage
prepared tests for DevNullAsyncStorage
prepared async cache
async base storage
storages moved to Sync or Async folders
created Async/Storage and Sync/Storage
async storage: rewritten verify and parseDependencies method
removed async flag from all child storages
prepared MemoryAsyncStorage (#6)
old names of storages are deprecated, added new names *Sync (#6)
tests for MemoryAsyncStorage
added many tests for sync and async base storages; optimizations (#6)
added tests for DevNullAsyncStorage and MemoryAsyncStorage for browser (#6)
added FileAsyncStorage (#6)
documentation for new storages and asynchronous access (#6)
using node.js async callback arguments style (#6)
Merge branch 'async'
Merge branch 'master' into develop