Renamed "SPage#hasLoaded" to "SPage#isLoaded"
Added some key utility methods to SPageComponent.

# isElementVisible(el)
# isElementLoaded(el)
+ waitForLoad(…)

This allows to have more fine-grained control over
the loading of Components in the page, if required.

The old good way of letting the SPage worry about it,
by just polling the "isLoaded" method sill works for
the majority of cases.
Updating tests to cover latest utilities.
Updating JavaDoc
Generated JARs for version 0.4.1