Add and test sum of absolute values math functions for CPU and GPU
Add and test element wise sign math funtions for CPU and GPU
Instantiate caffe_cpu_sign for float and double
Add and test element wise abs math functions for CPU and GPU
Use macro to simplify element wise cpu math functions
Add and test non-in-place scale math functions for CPU and GPU
Add signbit math func, simplify GPU defs & instantiations with a macro
Rename signbit in macros to sgnbit to avoid conflicts with std::signbit
Fixed CPPLint errors related to math funtions
Merge pull request #201 from kloudkl/more_math_functions

Add more convenience math functions and all tests pass
Separate ImagesLayer::Forward_gpu into a cu file
Separate WindowDataLayer::Forward_gpu into a cu file
Add headers to build on OS X
fixed compilation error on window_data_layer.cu in 10.8
Fix feature extraction reference model path and file list command bugs
Add in doc how to remove leveldb dir if existed
Fix imagenet pretrained links
Add packages installation command for CentOS/RHEL
removing lena in favor of cat
Merge pull request #260 from kloudkl/fix_doc_typos

Fix doc typos