[docs] install update: dependencies, CPU-only, Ubuntu 14.04

- update dependency versions
- document CPU-only build
- add Ubuntu 14.04 details
- include LMDB
- warn about defective CUDA driver series 331.*
link OpenBLAS as blas

OpenBLAS is most easily configured by `update-alternatives` or other
symlink strategies.

See https://github.com/BVLC/caffe/issues/314#issuecomment-40703048
[docs] contact us on webpage
[fix] adding requirements.txt for web_demo. Closes #704
[example] standardize imagenet leveldb names
[docs] announce caffe-users
[example] include image dimensions for oversampling
Merge pull request #825 from shelhamer/mailing-list

Announce caffe-users mailing list
[example] fix imagenet classification typo
Included cmath in common.hpp to avoid isnan complaints from the xcode compiler
turns out you need using::isnan too
the compiler complains about solver tests using pointers as bool
lint
fixed unnecessary conversions in test_solver, and rearraged common.hpp a bit
fix compiler complaint in matcaffe
Test that DropoutLayer obeys dropout_ratio.
Merge pull request #839 from jeffdonahue/test-dropout-ratio

Test that DropoutLayer obeys dropout_ratio
Add script to speedtest imagenet (currently broken as FilterNet ignores
Caffe::phase()).
Add tests for phase filtering according to Caffe singleton phase
(currently failing as FilterNet ignores the singleton phase).
Fix speedtest (and possibly other tools) by setting the net phase to the
current Caffe::phase() unless explicitly specified in the state.