[BUG] Small issues with Symbols

Moin!

Here are a few cases where I think different behavior would be more 
appropriate:

1) alias :"foo" :"bar"
This doesn't work at all right now. I think changing the syntax rule for 
this was forgotten when the :"" symbol syntax was introduced.

2) Symbol#inspect sometimes returns invalid symbol representations:
:"!".inspect # => :!
:"=".inspect # => :=
:"0".inspect # => :0
:"$1".inspect # => :$1  --  see also 5)
:"@1".inspect # => :@1
:"@@1".inspect # => :@@1
:"@".inspect # => :@
:"@@".inspect # => :@@

3) Symbol#inspect sometimes returns suboptimal symbol representations:
:foo!.inspect # => :"foo!"
:bar?.inspect # => :"bar?"

4) :$- always treats next character literally:
eval ":$-\n" # => :"$-\n"
:$-( # => :"$-("
:$-  # => :"$- "
:$-#.id # => 3950350

5) Inconsistency between :$0 and :$1? The first one is valid, but the 
latter isn't.

Regards,
Florian Gross