sdk-manual: Updates to "Working With Eclips" for Neon

sdk-manual: Updates to "Working With Eclips" for Neon

Fixes [YOCTO #7546]

Applied changes throughout this section to move it from Luna to
the Neon version (latest) of Eclipse.  We now provide a single
thread for Eclipse, which is based on the latest version (Neon).
Information for Mars, which is also supported) is in a new Appendix
C.

(From yocto-docs rev: 82995d9c49e4c55707591a1375c5d86874c589b0)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>