add required dependency on Debian/Ubuntu system
Rebased the following three commits onto one another:

1. Following GitHub convention by adding a CONTRIBUTING.md file.

2. Linking to the wiki page for communicating.

3. Referencing the waffle.io page for Neovim.
Fix Markdown syntax.
#165 fix README.md for Building OS X
Merge pull request #166 from rkmathi/issue-165

#165 fix README.md for Building OS X
Merge pull request #157 from Hywan/readme

Fix Markdown syntax
Merge pull request #123 from jbranchaud/adding-contributing-doc

Following GitHub convention by adding a CONTRIBUTING.md file.
Merge pull request #134 from HungMingWu/master

add required dependency on Debian/Ubuntu system
CMake: add LibUV_USE_STATIC configuration variable

If LibUV_USE_STATIC is set then the static libuv library will be
preferred to the shared library. This is useful when building with the
bundled libuv but is less useful when building with a system libuv.
Makefile: use static linkage with bundled libuv

Use the new LibUV_USE_STATIC configuration flag to use static linkage
when using the bundled libuv.
Merge pull request #172 from rjw57/issue-171

use shared libuv library if not using the bundled version
Add configuration to help debug memory leaks
Temporarily remove valgrind check in travis build
Add valgrind suppression file