RFR: 8279918: Fix various doc typos

[Pavel Rappo]

- Most of the typos are of a trivial kind: missing whitespace.
- If any of the typos should be fixed in the upstream projects instead, please say so; I will drop those typos from the patch.
- As I understand it,   in ImageInputStream and DataInput is an irrelevant formatting artefact and thus can be removed.
- ' is an apostrophe, which does not require to be encoded.

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.java.net/jdk/pull/7063/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7063&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8279918
  Stats: 85 lines in 34 files changed: 0 ins; 0 del; 85 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7063.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7063/head:pull/7063

PR: https://git.openjdk.java.net/jdk/pull/7063