[build,src,doc] Modify get_version.sh to deal better with whitespace (avoid space in version); minor fixes (#1526)

[scripts,egs] Adding options for using PCA instead of LDA+MLLT for ivectors used in ASR. Results are reported in the default TDNN recipe in AMI. Updating steps/online/nnet2/{train_diag_ubm.sh,train_ivector_extractor.sh} so that they now backup the contents of their destination directory if it already exists. (#1514)

[src] (minor) Added missing SetZero() to NaturalGradientAffineComponent::Scale() if scale==0.0 (#1522)

this improves speed when using hashes.

[egs] ami : Added tdnn_lstm recipe with fast-lstmp layer. Added tdnn_lstm recipe with -1 delay at lowest lstm layer (#1505)

swbd : Added tdnn_lstm recipe with delay -1 at the lowest lstm layer

[scripts] fix_data_dir.sh, prevent function returning false in case reco2file_and_channel does not exist (#1467)

Search for new-style http://kaldi-asr.org/doc/queue.html for an explanation of the difference.  It makes switching to new queueing mechanisms easier.