Remove `ValueSum::from_raw`

There is no reason for crate users to be constructing `ValueSum`
directly. We no longer use it to represent `valueBalanceOrchard`,
instead requiring the user to specify their own type.

CHANGELOG.md

@@ -6,4 +6,8 @@ and this project adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Removed
+- `orchard::value::ValueSum::from_raw`
+
+## [0.1.0-beta.1] - 2021-12-17
 Initial release!

src/value.rs

@@ -131,7 +131,7 @@ impl Sub for NoteValue {
     }
 }
 
-/// A sum of Orchard note values
+/// A sum of Orchard note values.
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
 pub struct ValueSum(i128);
 
@@ -140,14 +140,6 @@ impl ValueSum {
         // Default for i64 is zero.
         Default::default()
     }
-
-    /// Creates a value sum from its raw numeric value.
-    ///
-    /// This only enforces that the value is a signed 63-bit integer. Callers should
-    /// enforce any additional constraints on the value's valid range themselves.
-    pub fn from_raw(value: i64) -> Self {
-        ValueSum(value as i128)
-    }
 }
 
 impl Add for ValueSum {