Rename Class

[andrews-unity]

currently Sbt is not very informative, possibly renaming it to what it actually is would be more useful to the users of this class :)

[wotakuro]

As you said "Sbt" is not very informative...
I just want that users put few characters on their code to use this.

I found that putting below codes meets my requirement.
"using StrOpe = StringOperationUtil.OptimizedStringOperation;"

( And change "Sbt" to "StrOpe". "StrOpe" is short for ”StringOperation" )

[wotakuro]

also changed the namespace.