feat(lib): switch to non-blocking (asynchronous) IO

BREAKING CHANGE: This breaks a lot of the Client and Server APIs.
  Check the documentation for how Handlers can be used for asynchronous
  events.

Cargo.toml

@@ -16,13 +16,15 @@ httparse = "1.0"
 language-tags = "0.2"
 log = "0.3"
 mime = "0.2"
-num_cpus = "0.2"
+rotor = "0.6"
 rustc-serialize = "0.3"
+spmc = "0.2"
 time = "0.1"
 traitobject = "0.0.1"
 typeable = "0.1"
 unicase = "1.0"
 url = "1.0"
+vecio = "0.1"
 
 [dependencies.cookie]
 version = "0.2"
@@ -40,16 +42,13 @@ optional = true
 version = "0.1.4"
 optional = true
 
-[dependencies.solicit]
-version = "0.4"
-default-features = false
-
 [dependencies.serde]
 version = "0.7"
 optional = true
 
 [dev-dependencies]
 env_logger = "0.3"
+num_cpus = "0.2"
 
 [features]
 default = ["ssl"]