- generalize identity matrix constructors for non-scalar types

- add constructors using labelPair for the row/column sizing information.
  For a SquareMatrix, this provides an unambiguous parameter resolution.

- reuse assignment operators

STYLE: adjust matrix comments

- additional operators:
  + compound assignment
  + inner product: operator&
  + outer product: operator^

- additional functions:
   - MatrixBlock methods: subColumn, subRow, subMatrix
   - L2 norms for matrix or column
   - trace, diag, round, transpose

- MatrixBlock methods: col(), block() are deprecated since their
  access patterns with (size, offset) are unnatural/unwieldy.

- verifications by test/Matrix/Test-Matrix

- add iterators, begin/end, empty() methods for STL behaviour.
  Use standard algorithms where possible
     * std::fill, std::copy
     * std::min_element, std::max_element

- access methods consistent with other OpenFOAM containers:
     * data(), cdata(), uniform()

- Use ListPolicy to impose output line breaks

- Can recover matrix storage for re-use elsewhere.
  For example, to populate values with 2D i-j addressing and later
  release it as flat linear storage.

- construct/assign moveable

- added minMax() function for Matrix

- additional inplace +=, -=, *=, /= operations

- add named methods at() and rowData() to Matrix.
  Allows a better distinction between linear and row-based addressing

- low-level matrix solve on List/UList instead of Field

Added 'typeOfInnerProduct' support to ensure the correct type is
returned from the matrix product operator.

Also added the Field outer-product operator returning a RectangularMatrix

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1535

This reverts commit c5bea524.

This reverts commit b18f6cc1.

the type it will become as a template argument.

Brought everything into line with this change.