General Improvements (#47)

* Introduce `Result` shorthand, re-export and rename `InternalError`

* Re-export some public API relevant types

* Move `deserialize`

* Remove branch in `i2osp`

* Make `serialize` and `serialize_owned` methods

* Update p256

src/lib.rs

@@ -472,8 +472,8 @@
 //!   VOPRF evaluations.
 //!
 //! - The `p256` feature enables using p256 as the underlying group for the
-//!   [Group](group::Group) choice. Note that this is currently an experimental
-//!   feature ⚠️, and is not yet ready for production use.
+//!   [Group] choice and increases the MSRV to 1.56. Note that this is currently
+//!   an experimental feature ⚠️, and is not yet ready for production use.
 //!
 //! - The `serde` feature, enabled by default, provides convenience functions
 //!   for serializing and deserializing with [serde](https://serde.rs/).
@@ -512,8 +512,8 @@ extern crate std;
 mod util;
 #[macro_use]
 mod serialization;
-pub mod errors;
-pub mod group;
+mod error;
+mod group;
 mod voprf;
 
 #[cfg(test)]
@@ -521,8 +521,13 @@ mod tests;
 
 // Exports
 
+pub use crate::error::{Error, Result};
+pub use crate::group::Group;
+#[cfg(feature = "alloc")]
+pub use crate::voprf::VerifiableServerBatchEvaluateResult;
 pub use crate::voprf::{
     BlindedElement, EvaluationElement, NonVerifiableClient, NonVerifiableClientBlindResult,
-    NonVerifiableServer, NonVerifiableServerEvaluateResult, VerifiableClient,
-    VerifiableClientBlindResult, VerifiableServer, VerifiableServerEvaluateResult,
+    NonVerifiableServer, NonVerifiableServerEvaluateResult, Proof, VerifiableClient,
+    VerifiableClientBatchFinalizeResult, VerifiableClientBlindResult, VerifiableServer,
+    VerifiableServerEvaluateResult,
 };