wlineedit - added class to reimplement virtual focusInEvent()

Needed to capture a focus event in a QLineEdit box in order to clear
the contents when the QLineEdit box gets focus. This allows us to
put hint text in the edit window and clear it when the user wants to
make input.
phystat.pro - added wlineedit class to the project.

Done automatically by Qt.
style.cpp - Change QLineEdit font from 14 to 12
metenglayout - Replaced QLineEdit with WLineEdit

WLineEdit reimplements focusInEvent to capture when focus enters
the edit box so we can clear the contents before editing.