RFR: 8282473: Refactor swing classes javadoc to use @throws instead of @exception

[Prasanta Sadhukhan]

Prevailing JDK coding practices use "@throws" rather than "@exception".
Refactor existing swing classes javadoc to use @throws

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Commit messages:
 - Fix
 - Fix
 - Fix

Changes: https://git.openjdk.java.net/jdk/pull/7644/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7644&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282473
  Stats: 533 lines in 114 files changed: 0 ins; 0 del; 533 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7644.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7644/head:pull/7644

PR: https://git.openjdk.java.net/jdk/pull/7644