CAY-1946 CDbimport improvements

Squashed commit of pull request by Alex Kolonitsky
	c1b44b73a6e6c52021817b94cd7e73dc35db6bff
	fe54732563076365e6bbefc2dd4ab37b7d8f4643
Conflicts:
	cayenne-server/src/main/java/org/apache/cayenne/access/DefaultDbLoaderDelegate.java

1) remove 'final' in loop parameters and private methods
2) remove public in interfaces
3) remove unnecessary casting
4) add {} for if operator
5) add @Deprecated for methods which marked as deprecated in comments
6) replace StringBuilder with simple string concatenation; since java 5 compiler can do this optimization by it self: http://docs.oracle.com/javase/specs/jls/se5.0/html/expressions.html#15.18.1.2
7) add more info into exceptions
8) move methods into class where it give most cohesion
9) make object fields final where it is possible
10) added DefaultDbLoaderDelegate to avoid all methods implementation where only one required
CAY-1946 CDbimport improvements

* removing dupe method that was likely added from another patch
CAY-1946 CDbimport improvements

* readding the stupid casts inside DbAdapters - Java 1.6 compiler is not smart enough
  to infer return to this:

[ERROR] /Users/cayenne/work/cayenne-github/cayenne-server/src/main/java/org/apache/cayenne/dba/openbase/OpenBaseSniffer.java:[47,16] incompatible types
[ERROR] found   : java.lang.Object
[ERROR] required: org.apache.cayenne.dba.DbAdapter
noop , testing commit emails
noop , testing commit emails