MSWMS consistency checks for data files

[Joern Ungermann]

The data files can be "wrong" in a number of ways, which will cause Exceptions or misbehaviour in WMS.

a) Datafiles may contain different Elevationlevels. The "first" one is used to identify the levels, the others then assume the same levels to be present

b) Datafiles may have the wrong order of dimensions. This will cause an IndexError, which is meaningelss to the typical user.

c)...?

[Reimar Bauer]

Implemented a check on proper order of dimensions for AutmaticDataAccess

Order must be time, [vert], lat, lon. Also some tidying up.

See issue #218

→ <<cset 320990a770d0>>

[Reimar Bauer]

wrong datafiles should be sorted off, that we only have to verify this once

[Joern Ungermann]

The new DefaultAccess class adresses b) a) is missing

[Reimar Bauer]

Added checks for consistent elevation levels within one dataset type

Fix issue #218

→ <<cset d754d883fe23>>