feat(client): introduce komorebi-client crate

This commit introduces the komorebi-client library crate for other Rust
applications to interact with a running instance of komorebi over Unix
Domain Sockets.

Currently the crate re-exports everything one might find in the
komorebi::State struct and everything that is publicly exposed in
komorebi-core.

Public types and methods are still lacking documentation, and this crate
should not be published on crates.io until this is no longer the case.

komorebi/src/lib.rs

@@ -170,7 +170,7 @@ lazy_static! {
             }
         })
     };
-    static ref DATA_DIR: PathBuf = dirs::data_local_dir().expect("there is no local data directory").join("komorebi");
+    pub static ref DATA_DIR: PathBuf = dirs::data_local_dir().expect("there is no local data directory").join("komorebi");
     pub static ref AHK_EXE: String = {
         let mut ahk: String = String::from("autohotkey.exe");