Warnings: remove spurious parentheses in if() expression

diydrones/apm_planner#40
Warnings: QDomNodeList::length() returns an int not a uint

diydrones/apm_planner#40
Warnings: fix out-of-order member initialization in constructors

diydrones/apm_planner#40
Warnings: remove defined but unused variables

diydrones/apm_planner#40
Warnings: Ensure no QLOG_XYZ statements are on {}-less if statements

QLOG_XYZ are macros that evaluate to an if..else statement.  If you use them with a {}-less if statement, then you get dangling else clauses which the compiler warns about
diydrones/apm_planner#40
Warnings: initialize variables before they are referenced

diydrones/apm_planner#40
Warnings: Explicitly create virtual destructors when other virtual methods exist

diydrones/apm_planner#40
Warnings: eliminate unused static functions

diydrones/apm_planner#40
Warnings: eliminate spurious if statements that are always false

diydrones/apm_planner#40
Warnings: Flag all unused parameters using Q_UNUSED

diydrones/apm_planner#40
Warnings: cast all QVariant::type() results to QMetaType::Type

diydrones/apm_planner#40