Small fixes

This MR fixes a bunch of smaller issues, making the following changes:

* Template parameters in the documentation are documented with `\tparam` instead
  of `\param`
* Superfluous semicolon warnings fixed
* Fixed the type of literals used to initialize float variables

Eigen/src/Core/util/Serializer.h

@@ -46,7 +46,7 @@ class Serializer<T, typename std::enable_if<
   /**
    * Serializes a value to a byte buffer.
    * \param dest the destination buffer.
-   * \param T the value to serialize.
+   * \param value the value to serialize.
    * \return the next memory address past the end of the serialized data.
    */
   EIGEN_DEVICE_FUNC uint8_t* serialize(uint8_t* dest, const T& value) {