Make sure dbcommand is disposed

[RogerKratz]

DbCommands created in GenericBatchingBatcher aren't disposed.

[fredericDelaporte]

I have qualified it as just a minor improvement instead of a major bug because in most cases with db commands, this disposal lack will not cause an unmanaged leak and will not prevent the command from being garbage collected.

If I am wrong, this fix should then be re-tagged, but also should then target 5.3.x and likely be back-ported down to the introduction of the generic batching batcher.

[RogerKratz]

Agreed, I think it's minor as well, no unmanaged leak when SqlCommand is used I think. Not even sure it matters GC perf wise (maybe GC.SuppressFinalize is always called internally in SqlCommand anyhow, haven't looked closely)?

Still good to have it fixed (as "minor", yes).

[RogerKratz]

....on the other hand it might cause an unmanged leak if an other DbCommand than SqlCommand is used. However, I don't know much about these, only thinking out loud now.

[hazzik]

@fredericDelaporte maybe for 5.3.6?

[fredericDelaporte]

Why not.

[fredericDelaporte]

Changing the base did not went well, so I have done it manually with a forced push.