Correct grammar for arrays and tables

Forbid the parser of interpreting the sole | character as an empty array
or the sole : character as an empty table (use |[] and :[] instead)
Correct syntax_error's what() column information

The line number was being shown instead of the column number
Add explicitly sized arrays tests
Make object empty by default
Create method for creating explicitly sized arrays

To create an explicitly sized array of size x, just send an implicitly
sized array as a message to the number x. Arrays bigger than x will be
trimmed; arrays smaller than x will be filled with ().
Merge branch 'master' of https://github.com/romariorios/rubberband