Refactors QR code

- Deprecates qrp, qrpfact and qrpfact!
- Adds trailing pivoted::Bool option to qr, qrfact and qrpfact!
- Reorganizes QR factorizations section so that methods common to QR,
  QRPackedQ, QRPivoted, QRPivotedQ are grouped together.
- Remove improperly cleaned up blob from merge
- Replace methods defining default parameters with methods with default
  parameter values
- Rename QRPivoted.jpvt to QRPivoted.pivots
Deprecates cholpfact, cholpfact!
Fix dimension finding to work for StridedMatOrVec

Revert A.hh[1] < eps to A.hh[1] == 0 testing for (\)(QRPivoted)