Fixing compilation

Bringing it up to date with Qt 5.2, and doing the Qwt linking with
CONFIG in the project file.
Compiler & cppcheck warnings

Changes to eliminate many warnings.
Renaming properties

Adopting the mProperty style.
Fixing constructor parameter names

Several constructor parameters had gotten renamed along with the
properties in the previous commit.
Cleaning up constructors

Cleaned up some constructor declarations and definitions.