Even more algorithm usage in ProjectExplorer

Add Utils::transform and anyOf that take a member function pointer.
Remove bestElementOr it's unused.

Use declval<T> in transform's return type, because msvc does evaluate
T() and for types that don't have simple constructor this fails.
Add std::remove_reference since decltype returns a reference for
lvalues.

Change-Id: I22248b226748eeb27af0d300182d574438d7f756
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Algorithms: Introduce helper Utils::equal

Takes a member (function) pointer and a value and returns a functor,
that takes a instance of the mfp's class and returns whether it's equal
to value. Sounds complicated, but is a common pattern that is easy to
understand.

Change-Id: Iaaeb90488d34ddfd6940dadd4c66705381198fee
Reviewed-by: Nikita Baryshnikov <nib952051@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>