Better debugging support and minor improvements

[ShafinKhadem]

Changes:

• show line and token number of 1st mismatch, Attempts to fix #5 .
• redirect stderr to stdout
• exclude lines starting with "DBG#~ ". Attempts to fix #29 (TODO: inform users about it)
• set new testcase time limit from 1st testcase instead of default
• catch IOException separately when writing input ("Broken pipe" or "Stream closed" error occurs frequently when program doesn't process whole input, especially when input is large. Before this change, those were uncaught and program was unnecessarily stuck.)
• Increase max output length from 300 kb to 16 mb
• Start maximized
• Monospace font (grid problems are hard to visualize with non-monospace font)

[dj3500]

Awesome, thank you! Apologies, but it will take me some time to review these changes.

[4x3lpri3t0]

@dj3500 First of all, thank you so much for having worked on this tool for so long and making it available to everyone.

That being said - Would it be possible to merge these improvements?