Better quote rule decision for tied options.

[mattdowle]

Closes #2404
Closes #2196
Thanks @franknarf1 for the great file!

It wasn't the jumps per se. The first 100 lines all had quoted fields which all contained a comma. The quoteRule was then bumped to 3 (meaning ignore quoting) because it found 100 consistent lines of 17 columns rather than 16 lines with that quoteRule (17 beat 16). I've changed it to only resolve ties (i.e. different ways to parse the same number of consistent lines) with a different sep and no longer the same sep but different quoteRule. The lower quoteRule (0=double and 1=escape) are the standard ones so those should (and now do) take preference in these tied cases.

That wrong quote rule was then causing the jump problem later. I've lessened the impact of that (it now skips sample jumps where there's a format error even after nextGoodLine) but there's more work to do on that.

The test file grr.csv is added to the test suite with 4 large columns removed to reduce the size from 860KB down to 283KB. It generated CRAN's >5MB warning at the original size. The columns removed are the ones with long strings (>100 chars) without any of the quoting features being tested.

First 16 lines from the test file with quoted fields highlighted :

[codecov-io]

Codecov Report

Merging #2436 into master will increase coverage by 0.04%.
The diff coverage is 97.56%.

@@            Coverage Diff             @@
##           master    #2436      +/-   ##
==========================================
+ Coverage   91.29%   91.33%   +0.04%     
==========================================
  Files          62       62              
  Lines       12026    12032       +6     
==========================================
+ Hits        10979    10990      +11     
+ Misses       1047     1042       -5

Impacted Files	Coverage Δ
src/fread.c	96.2% <97.56%> (+0.45%)	⬆️

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[st-pasha]

Does this also solve #2196 ?

[mattdowle]

@st-pasha Yes. I'll add a test to this PR ...