move with_translation_unit_and_specific_location() to helpers.hpp
add lib/libclang-vim/deduction.hpp
add API interfaces to deduct type at specific location
add helper to get a specific kind cursor
add a function to get type of variable declaration

it's work in progress. auto type deduction is TODO
deduct from right hand side expression

this is incomplete
use -std=c++11 to deduct types correctly

this is TEMPORARY implementation
use -std=c++11 to deduct types correctly

this is TEMPORARY implementation
deduct if the cursor is invalid
Merge branch 'deduct_auto' of github.com:rhysd/libclang-vim into deduct_auto

Conflicts:
	lib/libclang-vim/clang_vim.cpp
fix for the case when kind of type is unexposed and type is not auto
Merge branch 'deduct_auto_var_decl'