Merging logstream branch into Malhar master

The logstream application can be found under apps directory. It contains both old and the new versions.
The old version has operators added to the dag for each type and filter. It emits the results to
redis db similar to siteops for siteops UI to consume. The new version is optimized to have a single
line of logical dag which partitions itself based on log types and filters applied on each type.
It also sends meta information to the each aggregation such as type, filter, dimension etc to uniquely
identify the aggregation. The results are emitted using the widget output operator to be viewed on
the new widgets UI.

For old version, please see apps/src/main/java/com/datatorrent/apps/logstream/Application.java
For new version, please see apps/src/main/java/com/datatorrent/apps/logstream/Application1.java
fixes #MLHR-836
Squashed commit of the following:

commit a0ba9e2774af2cae992359aedf32820840677274
Author: Nick Holub <nikholub@gmail.com>
Date:   Wed Mar 5 14:59:56 2014 -0800

    fix #MLHR-864 Installer - Handling Hadoop Not Found

commit ed57803f6014fd219bf921a9c795773ee5c51659
Author: Nick Holub <nikholub@gmail.com>
Date:   Wed Mar 5 14:45:29 2014 -0800

    fix #MLHR-819 Installer - System Properties Section
Merge pull request #750 from nickholub/inst7_pull

Installer Update - Handling Hadoop Not Found
Merge pull request #749 from gauravgopi123/MLHR-836

fixes #MLHR-836 - A new customizable AbstractHDFSOutputOperator!
Merge pull request #734 from ashwinchandrap/to_upstream_master_from_ls_0.9.4

Merging logstream branch into Malhar master
Squashed commit of the following:

commit ef099e16e56d1de662777dfc8fd67c05510b385d
Merge: e12778c e49c560
Author: RashmiDR <rashmi@datatorrent.com>
Date:   Wed Mar 5 17:59:48 2014 -0800

    Merge branch 'master' of https://github.com/DataTorrent/Malhar into directoryScan2014

commit e12778cbe1f0365c63a0a7853a184ec5bae73cca
Author: RashmiDR <rashmi@datatorrent.com>
Date:   Wed Mar 5 17:46:19 2014 -0800

    fixing additional review findings for Directory Scan operator, fixes #MLHR-321
Merge pull request #752 from RashmiDR/directoryScan2014_pull

Squashed commit of the following: