Add tools to extract x, F, and J from the trace.

[pkofod]

Fixes #246 by adding x_trace, F_traceand J_trace. extended_trace has to be set to store arrays and not just norms.

[codecov]

Codecov Report

Merging #262 (118fb0b) into master (e5967ca) will decrease coverage by 0.32%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #262      +/-   ##
==========================================
- Coverage   87.57%   87.24%   -0.33%     
==========================================
  Files          12       13       +1     
  Lines         531      541      +10     
==========================================
+ Hits          465      472       +7     
- Misses         66       69       +3     

Impacted Files	Coverage Δ
src/NLsolve.jl	66.66% <ø> (ø)
src/trace_tools.jl	100.00% <100.00%> (ø)
src/solvers/broyden.jl	71.42% <0.00%> (-3.30%)	⬇️

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