[FEATURE] Calculate coverage for a simple single condition

Resolves: #19
[FEATURE] Coverage for simple AND/OR expressions

This adds coverage for simple compound expressions that have boolean
values on both sides. In these cases, coverage can directly be derived
from the values. For more complex cases, we will have to first derive
the boolean value of a subordinate expression and then calculate the
coverage.
[BUGFIX] Broken constructor call in tests
[TASK] Rename BreakpointDataSet to DataSample

The new name much better fits the actual purpose of the class.
[TASK] Rename StaticAnalysis\Breakpoint to Probe
[BUGFIX] Analysis output file cannot be specified
[FEATURE] Use injected coverage data object in test run
[FEATURE] Allow single root node for syntax tree iterator
[FEATURE] Fetch values by evaluation

This allows for fetching values of arbitrary expressions by using the
"eval" command of DBGp.
[TASK] Make PHPUnit arguments an explicit option
[TASK] Change value fetcher precedence

The evaluate fetcher can be used for any expression, so we use it as
a fallback if the property fetcher cannot be used.
[BUGFIX] Debugger client loop not exited after tests
[FEATURE] Store collected coverage data

Currently, the object is simply serialized. Later on, we should move
this to an XML/JSON based format.
[TEST] Acceptance test for single condition decisions

The test is currently not that valuable for protection against
regressions (though it already tests quite a bit of the functionality),
but it is rather meant as a quick means to test the complete process
from static analysis to coverage calculation.

To run the test, execute
`phpunit -c Build/PhpUnit/FunctionalTests.xml Tests/Acceptance/Coverage`
from the main directory.
[FEATURE] Attach probe to syntax tree node
[CLEANUP] Remove unused truth table class
[BUGFIX] Session constructor should not be called in unit tests
[FEATURE] Get values from data sample