index_entry: Added missing fields.

This adds dev, ino, mode, uid, gid, file_size, oid, flags, and flags_extended, which were previously omitted.

Fixes #94.
Regenerated include/index_entry.h and src/index_entry.cc after new fields were added.
Merge pull request #95 from papandreou/addMissingFieldsToIndexEntry

Add missing fields to index entry
new add and remove file example
cmake 2.8 is required to build nodegit

The "--build" option appeared in 2.8, some distros such as rhel provide cmake 2.6 by default and it can take a while to figure why the build fails.
Merge pull request #100 from dcolens/patch-1

cmake 2.8 is required to build nodegit
Fixed method names in reference example

fixes #98
Fixed wrong variable name.
Fixed unknown oid for general examples
Fixed unknown commit oid
Merge pull request #99 from dcolens/master

new add-and-commit.js and remove-and-commit.js examples
Changed default value of working dir to a existing git folder
Merge pull request #102 from micha149/example-fixes

Reviewd and fixed examples