Extract out some code from Code class
Extract out some code from Code class

Create a new class called `LOC`, which represents a tuple of a line and
a line number (lineno). `LOC` contains methods that operate on a line.
For example, you can colorize it, or add a line number. The idea is to
make the code of `Pry::Code` more readable. It is clear to me that the
current code allows us to single out a new unit: a line of code.

Signed-off-by: Kyrylo Silin <6129bf6f04030cd1423e4f3df28402e79fbf30a4@gmail.com>

jasnow/pry,caporta/pry,josue804/debunker,ngpestelos/pry,shockone/pry,icebreaker/pry,tdg5/pry,85x14/pry,85x14/pry,tdg5/pry,gfvcastro/pry,printercu/pry,richo/pry,caporta/pry,nju520/pry,sferik/pry,shockone/pry,ooohiroyukiooo/pry,bronzdoc/pry,icebreaker/pry,pvdb/pry,geoffreylitt/pry,scalixte-mdsol/pry,deivid-rodriguez/pry,raeno/pry,ooohiroyukiooo/pry,jasonm23/pry,tdg5/pry,gfvcastro/pry,sideci-sample/sideci-sample-pry,nju520/pry,ooohiroyukiooo/pry,85x14/pry,jasonm23/pry,scalixte-mdsol/pry,geoffreylitt/pry,printercu/pry,raeno/pry,raeno/pry,pvdb/pry,jasonm23/pry,scalixte-mdsol/pry,josue804/debunker,bronzdoc/pry,sferik/pry,ngpestelos/pry,caporta/pry,nju520/pry,jasnow/pry,jasnow/pry,shockone/pry