Many lines were not conformant with the project's formatting rules.
This patch should fix all formatting and whitespace issues in the code
base.
A clang-format directive was put around the connect() calls containing
SIGNALs and SLOTs whose signatures would be denormalized because of the
formatting rules.
Use nullptr instead of 0 or NULL to initialize a null pointer. In some
cases, readability was enhanced by replacing 0 with more meaningful
values according to the type of the pointer being initialized.
