Wait before reporting error-counts

Original the get-counts(-log) only checked whether the log-file
contained additional lines. This way errors that currently are processed
by the logging-system or that haven't been flushed to file by the OS are
not visible. Waiting for 300 ms is not a fail-save solution, but it
helps.
Separated sql-except reporting for reuse

Sql-exception reqporting requires looking for the next error.
The code that does this two-level check is separated for reuse
in vSql.
Added routine to do a generic chuncked write.

Via a binary search the data is writen to database. If one
row fails this specific row will be omitted. A binary write is fast
when only a limited number of rows fail as it tries to write big blocks.

Note when a now() field is part of the key the chunked write might even
resolve a key-conflicts as different batches have a slightly different
time of insertion (with TIMESTAMPS, not with DATE-TYPES).
Extende clj-excel (read xls) and vCsv

Now clj-excel read a rectangular area via get-lazy-sheet.
Nil-patching is applied to fill gaps by empty cells, as these
aren't included in the poi iterators over rows and columns.

Furthermore small patch to vCsv to prent is fails on nil fields.
(apply str before doing a trim).