Move util.rs to common
Groom id/id.rs to work with util.rs
whoami and id use c_types
Merge pull request #107 from alan-andrade/common

/common for code reusability
Make the capitalization of Rust consistent
logname implementation
Merge pull request #110 from humboldtux/master

logname implementation
Update for new programs
id and groups share functions
Merge pull request #114 from alan-andrade/groups

Groups
Fix for latest Rust
Merge pull request #115 from Arcterus/master

Fix for latest Rust
Merge pull request #116 from uutils/master

Update dev