Added current date time placeholder function name.

If the function name is matched in UpdateGenerator or InsertGenerator, the value is replaced with the real current datetime.
Using current_datetime as the placeholder.
Updated test xml with an example.
Either valueComputed or valueDate can be used to set the value.

Removed redundant castings in Column.java and unused methods.
Added support for setting a sequence's current or next value as a default value.
Refactored SequenceFunction into SequenceNextValueFunction and SequenceCurrentValueFunction.
Both now extend DatabaseFunction.
Added method to database to generate the real value for a database function.
Added tests for the new functionality.
Added 3.0 changelog info
getBoolean needs to handle string objects
added some compile locations to gitignore
Merge branch 'sequenceComputed' of https://github.com/vorbis/liquibase into vorbis-sequenceComputed

Conflicts:
	liquibase-core/src/main/java/liquibase/change/ColumnConfig.java
	liquibase-core/src/main/java/liquibase/change/core/AddAutoIncrementChange.java
	liquibase-core/src/main/java/liquibase/database/core/H2Database.java
	liquibase-core/src/main/java/liquibase/database/core/HsqlDatabase.java
	liquibase-core/src/main/java/liquibase/database/core/OracleDatabase.java
Finish merge branch 'sequenceComputed' of https://github.com/vorbis/liquibase into vorbis-sequenceComputed
Merge branch 'currentDateTimeComputed' of https://github.com/vorbis/liquibase into vorbis-currentDateTimeComputed

Conflicts:
	liquibase-core/src/main/java/liquibase/database/AbstractJdbcDatabase.java
	liquibase-core/src/main/java/liquibase/database/core/DB2Database.java
	liquibase-core/src/main/java/liquibase/database/core/DerbyDatabase.java
	liquibase-core/src/main/java/liquibase/database/core/H2Database.java
	liquibase-core/src/main/java/liquibase/database/core/HsqlDatabase.java
	liquibase-core/src/main/java/liquibase/database/core/InformixDatabase.java
	liquibase-core/src/main/java/liquibase/database/core/MaxDBDatabase.java
	liquibase-core/src/main/java/liquibase/datatype/LiquibaseDataType.java
	liquibase-core/src/main/java/liquibase/sqlgenerator/core/InsertGenerator.java
	liquibase-core/src/main/java/liquibase/sqlgenerator/core/UpdateGenerator.java
	liquibase-core/src/main/java/liquibase/structure/core/Column.java
Finished merge branch 'currentDateTimeComputed' of https://github.com/vorbis/liquibase into vorbis-currentDateTimeComputed
changed version name to 3.0.0-beta1
NotNull annotation seemd to be confusing maven
maven not doing a release:prepare successfully
integration-tests seem to not be allowing maven to release:prepare property
[maven-release-plugin] prepare release liquibase-parent-3.0.0-beta1
[maven-release-plugin] rollback the release of liquibase-parent-3.0.0-beta1
use https github connection to not have to deal with ssh with release. Going to try beta1 release again