Added copyright tag to files
Fixed @since tag in files

After reading the phpDocumentor’s docs, I realized the @since tag
should use a semantic version number, not a date.
Added on/off to Str::isBool() method
Fixed logic error in Bool::val()

Well, I forgot to handle the case where the $var argument was already a
bool. The code didn’t do anything with it haha.
Added comments to Str::strtobytes()

I forgot to include the “// no break” comments.
Updated Bool's comments to DocBlock2
Refactored Num class

I renamed function arguments, added code to test the validity of
arguments, fixed comment syntax, and fixed a few logic and variable
name errors.
Refactored Bool class

I renamed a few arguments and variables and fixed comments.
Refactored Str class

I renamed arguments, added logic to test arguments’ validity, fixed
comments, and fixed a few bugs here and there.
Refactored Arr class

I updated argument names, added tests for argument validity, and fixed
comment syntax.
Removed BoolTest class

Well, actually, I emptied it, but the result is the same. Those weren’t
good unit tests.
Added StringTest class

Eh, I’m not a huge fan of these tests. I’ll probably have to re-do
them. I don’t think they’re correct (i.e., they’re testing for bugs not
behaviors).