some unittest macros behave wrong (double eval fix)

[westram]

Status quo:

• r15453 "fixed" a double evaluation problem for TEST_EXPECT_EQUAL__BROKEN
• a similar problem exists for TEST_EXPECT_IN_RANGE

New problems introduced by "fix" r15453:

• the expressions are not dumped as specified in client code (instead dump local variable names)
• the dumped location is wrong (points to test_unit.h) by [16355]

Might be solvable by introducing new methods, e.g.

• is_broken_equal(want,got)
• is_in_range(lower,upper)

These methods shall not return a match_expectation (as is_equal_to(...) does). Instead it could create an expectation_group or similar containing the 2 involved expectations and then use a special method instead of expect_broken()/expect_that().