Update run-example

Old code can only be ran under spark_home and use "bin/run-example".
 Error "./run-example: line 55: ./bin/spark-submit: No such file or directory" appears when running in other place. So change this

Author: maji2014 <maji3@asiainfo-linkage.com>

Closes #1011 from maji2014/master and squashes the following commits:

2cc1af6 [maji2014] Update run-example

Closes #988.
(cherry picked from commit e9261d0866a610eab29fa332726186b534d1018f)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
[SPARK-2067] use relative path for Spark logo in UI

Author: Neville Li <neville@spotify.com>

Closes #1006 from nevillelyh/gh/SPARK-2067 and squashes the following commits:

9ee64cf [Neville Li] [SPARK-2067] use relative path for Spark logo in UI
(cherry picked from commit 15ddbef414d5fd6d4672936ba3c747b5fb7ab52b)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>