Handle string based dates better

Get-ymd now also handles dates with single digit months and days to
2013-1-1 is parsed just like 2013-01-01
Allow multi-column contstraints

Multi-column constraints are represented as field-definitions with a containt
but no type information.
For all field-definitions either :tpe or :constraint needs to exists.
Improvement in class-path parsing.
Added stripping of leading strings (prefixes)
Comments and small things
Changed vProps to return hash-map

Preveously the get-properties returned a java.util.Properties object,
which behaves like an hashmap, but does not allow certain operations
like assoc.
Code of vinzi.pentaho and vinzi.eis needed to be adapted too.
Fixed vSql/get-col-info to be mysql compatible.
Added get-last-modified.

Retrieve the last modification time and return it as a string.
Extended vSql with sql-strings, schema operations and..

- Function to transform a string to a date-string that can be passed
as a literal to an sql-statement.
- Function to create a schema
- Extended create-table to recognize date fields
Extended vCsv, vDateTime and vFile

-vCsv:  added functions to check type of options in write-csv
-vDateTime:  generate string that can be used as literal in
   an sql statement.
-vFile: only comments
Added update-recs and get-sql-str-val

update-recs does an update over a table where the update
is limited to the values present in a record.

Also added get-sql-str-val that turns a value in a string that
can be used in an sql statement. This function does not do
typechecking on the provided values.
Fixed error in parameters-check of write-csv.
Added leinProj and some updates

vDate: added timeZone related functions
vProject: added fix for to pomtoproj (missing items in pom.xml crashed code)
Transform string to regexp search pattern.

Not well tested yet.
Fix of (get-timestamp)
Added the (memory-tracker) utility

Periodic check of free memory.
To extend with a time-stamp.
Extended memory-tracker, added set-log-file) and string-to-inputstream

I
Added memory tracking to vLogfile
Added conversion of clojure.xml->clojure.data.xml

Clojure.data.xml has documented emit routines, but
these do not operate on the persistent hashmaps (of clojure.xml).