Implement JLine constructor

A body to the JLine constructor was added.  This body calls the
removeComments function, which strips out the commented parts of a given
line and returns the pure code.
Add body to JLine::removeComments()

The body for removeComments() is a pirated version of the code used in
previous editions of the JCodeFile::trimComments() function.

removeComments() is a recursive function that eliminates the first
ocurrence of a comment in a line, and processes the remaining string.
Remove commented-out function trimComment