Added bash script to parse log 

To save the log file during training do
```
GLOG_logtostderr=1 ./build/examples/train_net.bin solver.prototxt 2> caffe.log
```
Usage:
```
parselog.sh caffe.log [init_iter=0] [test_interval=1000]
```
This script extracts the training losses into caffe.log.loss
And the test loss and accuracies into caffe.log.test

I hope it helps to #86