Spreadsheets with no bounding frame

[jazzido]

(as commented in jazzido/tabula#128)

There are spreadsheets with no outer frame.

Proposed fix: build a frame that encloses all the characters in the target area, and use it to clip all the rulings inside it. This, in fact, can be done whether the spreadsheet has a bounding frame or not.

[jeremybmerrill]

picking this up, with this spreadsheet http://www.conab.gov.br/OlalaCMS/uploads/arquivos/13_06_12_10_36_58_boletim_ingles_junho_2013.pdf (I'll find a relevant page and stick it in the test set)

[jeremybmerrill]

I implemented this by building the frame to enclose all ruling lines in the target area -- rather than characters. My alternative is more likely to work in all cases for the spreadsheet algorithm, which depends on lines intersecting (or very nearly intersecting).

Is there a case in which building the frame using characters is superior? Unless I'm mistaken, the "original" method would ignore the frame no matter what, right?

[jeremybmerrill]

My solution (33abbdb) causes test_issue78_some_ruling_lines_not_detected to fail. I think the failure is due to a typo fixed in f16eb31 and the new, actual result is a proper result (it basically returns an additional row).

[jeremybmerrill]

Can you verify, @jazzido ?