Update unicode.pl

Add /charblocks to list all the Unicode blocks (e.g. /grep -i math /charblocks will list all blocks with math symbols) and display the perl literal strings for each character.
Example:
/unicode ☎ 
☎ (U+260E): BLACK TELEPHONE
block=Miscellaneous Symbols, category=So, perl=\xe2\x98\x8e, script=Common
This information can be used for /eval (e.g. /eval /echo The \xe2\x98\x8e is ringing!)