Fix shy #1313 (#1319)

* Fixed bugs regardings soft hyphen handling and simplified the code.

* Fixed left-align, right-align, center-align.

* Fixed jusitied alignment, mostly. It does not work correctly in all cases, because letter-spacing is not applied between letters of the same word at style boundaries.

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/content/ITextContent.java

@@ -18,7 +18,7 @@
  * Provides the interfaces for the Text Content Text content contains several
  * paragraphs which shares the same style properties.
  *
- * If the text contain serveral return characters and the display is inline, it
+ * If the text contain several return characters and the display is inline, it
  * is treated as "INLINE-BLOCK" otherwise it is "INLINE".
  *
  * If the display is "block", it is "BLOCK" always.

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/hyphen/Word.java

@@ -35,38 +35,6 @@ public class Word {
 	protected int end;
 	protected String text;
 
-	private boolean keepTrailingSoftHyphen = true;
-
-	/**
-	 * Should a trailing Unicode SOFT HYPHEN (SHY) symbol be kept or omitted?
-	 *
-	 * @return true if a trailing soft hyphen should be kept, false if it should be
-	 *         omitted.
-	 *
-	 * @since 4.13
-	 */
-	public boolean isKeepTrailingSoftHyphen() {
-		return keepTrailingSoftHyphen;
-	}
-
-	/**
-	 * Set whether a trailing Unicode SOFT HYPHEN (SHY) symbol should be kept or
-	 * omitted. The default value is <tt>true</tt>, so this is usually only called
-	 * to omit it.
-	 *
-	 * @apiNote This is not really used inside the Word class. But a Word object is
-	 *          used to transmit the information piggyback to the
-	 *          {@link org.eclipse.birt.report.engine.nLayout.area.impl.TextArea}
-	 *          object, where the information is needed.
-	 *
-	 * @param keepTrailingSoftHyphen whether to keep the last soft hyphen or not.
-	 *
-	 * @since 4.13
-	 */
-	public void setKeepTrailingSoftHyphen(boolean keepTrailingSoftHyphen) {
-		this.keepTrailingSoftHyphen = keepTrailingSoftHyphen;
-	}
-
 	/**
 	 * Create a Word instance as a substring of a given text.
 	 *

engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/text/Chunk.java

@@ -18,6 +18,10 @@
 
 import com.ibm.icu.text.Bidi;
 
+/**
+ * A Chunk is a piece of text and formatting metadata like what font to use and
+ * BIDI setting. The font info is needed for computing width and height.
+ */
 public class Chunk {
 	private String text;
 	private int offset;
@@ -92,7 +96,7 @@ public int getBaseLevel() {
 	}
 
 	/**
-	 * Sets direction of this chunk.
+	 * Sets run level of this chunk.
 	 *
 	 * @param runLevel An integer value from 0 to 62
 	 *