Return from eval failure

[tyronerees]

Closes #37

I've left things as they are on the first call, as if you can't evaluate the Jacobian/function at the initial guess, the user should pick a different point.

I have not addressed the eval_HP issue mentioned in #43

[codecov[bot]]

Codecov Report

Merging #49 into master will increase coverage by 0.7%. The diff coverage is 96.1%.

@@            Coverage Diff            @@
##           master      #49     +/-   ##
=========================================
+ Coverage   87.85%   88.55%   +0.7%     
=========================================
  Files           4        4             
  Lines        2619     2631     +12     
=========================================
+ Hits         2301     2330     +29     
+ Misses        318      301     -17

Impacted Files	Coverage Δ
libRALFit/src/ral_nlls_internal.f90	91.14% <96.1%> (+1.11%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update c110356...f7f0645. Read the comment docs.

[codecov[bot]]

Codecov Report

Merging #49 into master will increase coverage by 0.7%. The diff coverage is 96.1%.

@@            Coverage Diff            @@
##           master      #49     +/-   ##
=========================================
+ Coverage   87.85%   88.55%   +0.7%     
=========================================
  Files           4        4             
  Lines        2619     2631     +12     
=========================================
+ Hits         2301     2330     +29     
+ Misses        318      301     -17

Impacted Files	Coverage Δ
libRALFit/src/ral_nlls_internal.f90	91.14% <96.1%> (+1.11%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update c110356...f7f0645. Read the comment docs.