Fixes for running Oracle Integration tests.

Added null checks for object name.
Oracle doesn't support setting a sequence as a default value so removed oracle from that test.

After the Diff refactoring, CreateTableChange is not having its columns serialized.
Issue is due to the method name getColumn in ChangeWithColumns.
This should be getColumns to match the expected getter name for columns.
Without this in CreateTableChange, the columns property won't be considered for serialization
as it won't have a valid read and write method.

I also encountered weird behavior with Oracle whereby an overly long description was correctly
limited to 255 characters but was for some reason being treated as 259 characters by oracle.
This thus resulted in a constraint violation as the length was then too long for the description.
Bit of a hack but I lowered the description length to 250 and that seems to work.
Fix for escaping index name on index creation.

Index name should be escaped on creation of an index.
Added integration test changeset for testing creation of an index using
the quoting strategy QUOTE_ALL_OBJECTS.

Simplified the escaping of objects for QUOTE_ALL_OBJECTS to quote all objects.
The original reason for smart quoting of objects is no longer needed.
It was in place when I was originally implementing this feature as I was quoting
in the correctObjectName method.
Add quoting character as a protected property in AbstractJdbcDatabase

I'll need to install Mysql to properly test databases where the quoting character
is not ". This approach will allow for specific databases to set the proper quoting character.
Fixes for MySQL integration tests.

Override quoting of object names by setting quoting characters as empty strings.
Removed incorrect correctObjectName code in MySqlDatabase.
Updated test AddNotNullConstraints with default null values.
Fixes for PostgresSQL tests.
When dropping all objects, use QUOTE_ALL_OBJECTS strategy as
the names that come back from the database metadata are case sensitive.
Removed defaultNullValue for intValue in AddNotNullConstraint.
The handling of the default value data type needs to be improved.
ints are treated as string values currently.

Added fix for CreateIndexChange to output in diffs correctly.
Getters and setters need to be present for a property for it to be
included.
CORE-1070
Preconditions should support parameters
Fixed quote char
Add approach for excluding databases from running changesets.

Use ! to exclude a dbms.
E.g. to prevent oracle from running a changeset use dbms="h2,!oracle,mysql"
The changeset will run for h2 and mysql but not for oracle.
Add ability to set dbms for raw sql changes.

Currently, you can only specify database names at the changeset level.
This commit extends that functionality for sql changes.
Useful for creating more compact change logs.

I'm not fully comfortable with the practive of injecting variables into a changelog from java.
If that is possible, I can move my integration test to common.tests.changelog and pass in the current
database short name so that the testing can be used for all databases.

Currently only testing using H2 but since this feature is just liquibase based it should work fine with
all databases.
MSSQL-Server in Version 10 does not support DropTableCascadeConstraints
Adding rollback file support.
Merge pull request #118 from vorbis/dbmsExclude

Add property for excluding databases from changesets.
Merge pull request #120 from jwcarman/master

CORE-1279: Generate Rollback Script File With SpringLiquibase
Json and Yaml changelog parse support generally works
Added new snakeyaml dependency for yaml/json changelog formats
Merge remote-tracking branch 'origin/master'

Conflicts:
	liquibase-integration-tests/src/test/java/liquibase/dbtest/h2/H2IntegrationTest.java
Merged in origin/master
Merge branch 'integrationTestFixes' of https://github.com/vorbis/liquibase into vorbis-integrationTestFixes

Conflicts:
	liquibase-core/src/main/java/liquibase/change/core/AddColumnChange.java
	liquibase-integration-tests/src/test/resources/changelogs/common/common.tests.changelog.xml
Merge branch 'dbmsChange' of https://github.com/vorbis/liquibase into vorbis-dbmsChange

Conflicts:
	liquibase-integration-tests/src/test/java/liquibase/dbtest/AbstractIntegrationTest.java
	liquibase-integration-tests/src/test/java/liquibase/dbtest/h2/H2IntegrationTest.java
Merge branch 'dbmsChange' of https://github.com/vorbis/liquibase into vorbis-dbmsChange

Conflicts:
	liquibase-integration-tests/src/test/java/liquibase/dbtest/AbstractIntegrationTest.java
	liquibase-integration-tests/src/test/java/liquibase/dbtest/h2/H2IntegrationTest.java