Miscellaneous matrix methods

[mgkurtz]

The call to hnf(A) gives a row echelon form, but no information about rank or pivots. These fast methods provide that information. (Without verifying the echelon form.)

Also fix the transpose! method, I have lately introduced.

[codecov]

Codecov Report

Patch coverage: 89.47% and no project coverage change.

Comparison is base (75eb599) 69.41% compared to head (618da5a) 69.42%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1138   +/-   ##
=======================================
  Coverage   69.41%   69.42%           
=======================================
  Files         349      349           
  Lines      113011   113036   +25     
=======================================
+ Hits        78444    78471   +27     
+ Misses      34567    34565    -2     

Impacted Files	Coverage Δ
src/Misc/Matrix.jl	70.74% <89.47%> (+0.33%)	⬆️

... and 40 files with indirect coverage changes

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[thofma]

Good idea to not export them, but then the doctests need the module prefix.

[thofma]

Thanks!

I am not too big of the cond || bla syntax. It is a bit hard to parse at a first glance (for errors it is fine, since it is usually clear what is checked). I will merge this as is, but maybe we can avoid it in the future.