Revision 553620

HADOOP-1531 Add RowFilter to HRegion.HScanner.
Adds a row/column filter interface and two implementations: A pager and a
row/column-value regex filter.
M src/contrib/hbase/src/java/org/apache/hadoop/hbase/HRegionServer.java
M src/contrib/hbase/src/java/org/apache/hadoop/hbase/HRegionInterface.java
    (openScanner): Add override that specifies a row fliter.
M src/contrib/hbase/src/java/org/apache/hadoop/hbase/HClient.java
    (obtainScanner): Add override that specifies a row fliter.
    (ColumnScanner): Add filter parameter to constructor.
M src/contrib/hbase/src/java/org/apache/hadoop/hbase/HRegion.java
    (getScanner): Add override with filter parameter.
    (next): Add handling of filtering.
A src/contrib/hbase/src/java/org/apache/hadoop/hbase/filter/InvalidRowFilterException.java
A src/contrib/hbase/src/java/org/apache/hadoop/hbase/filter/RegExpRowFilter.java
A src/contrib/hbase/src/java/org/apache/hadoop/hbase/filter/RowFilterSet.java
A src/contrib/hbase/src/java/org/apache/hadoop/hbase/filter/PageRowFilter.java
A src/contrib/hbase/src/java/org/apache/hadoop/hbase/filter/RowFilterInterface.java
    Row-filter interface, exception and implementations.
A src/contrib/hbase/src/test/org/apache/hadoop/hbase/filter/TestRegExpRowFilter.java
A src/contrib/hbase/src/test/org/apache/hadoop/hbase/filter/TestPageRowFilter.java
    Simple pager and regex filter tests.