Fix #217 : Line count should start at 1 not 0

When comparing file content the line number in diff
should start at 0 instead of 1.
New Map assertion : hasSameSizeAs(Map<K, V> other) - Fixes #213
Add Iterable assertion: hasSameElementsAs(Iterable<T> other) which is an alias for containsOnlyElementsOf - Fixes #219
Improve InputStreams.assertEqualContent message
Improve InputStreams.assertEqualContent message - Fixes #227
Add haveAtLeastOne(condition) to ObjectEnumerableAssert as an alias for haveAtLeast(1, condition) - fixes #185