RFR: 8294948: Document IllegalArgumentException and NullPointerException thrown by URLStreamHandler::parseURL and URLStreamHandler::setURL [v8]

[Daniel Fuchs]

> During the review of JDK-8293590, it was noted that some methods in `URLStreamHandler` were missing an `@throws IllegalArgumentException` clause in their API documentation. 
> 
> This change adds the requested information, and also clarifies throwing `MalformedURLException` from URL constructors.
> 
> The CSR can be reviewed here: https://bugs.openjdk.org/browse/JDK-8294984

Daniel Fuchs has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 10 additional commits since the last revision:

 - More review comments
 - Taking into account review feedback
 - Merge branch 'master' into url-iae-8294948
 - Merge branch 'master' into url-iae-8294948
 - Minor wording updates - unmmapable single quote character
 - Minor wording updates
 - Update Copyright Years
 - Adding missing @throws NPE
 - 8294948
 - 8294948

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/10609/files
  - new: https://git.openjdk.org/jdk/pull/10609/files/772536cc..f0259f10

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10609&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10609&range=06-07

  Stats: 11711 lines in 235 files changed: 7969 ins; 2246 del; 1496 mod
  Patch: https://git.openjdk.org/jdk/pull/10609.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10609/head:pull/10609

PR: https://git.openjdk.org/jdk/pull/10609