22x speed improvement, 3X mem impovement

data = apply(matrix(as.character(1:90000), ncol= 300), 1, paste, collapse = " ")
system.time(readPartition(data))
system.time(readPartition.old(data))
faster parsing
replace require with library

require is used only when there is a way to recover from a failure to
load a package. Since these examples would all fail if any of the
missing libraries were required, using require only delays the error
and makes it less clear.
implemented using matrices and vectorized calls wherever possible
for rstudio users
vectorized version, 36s 10 slices 10^6 per slice. The older version takes 30 sec on 1/10th of data.
Exclude protobuf from Spark dependency in Maven
This avoids pulling in multiple versions of protobuf from
Mesos and Hadoop.
Merge pull request #34 from shivaram/master

Exclude protobuf from Spark dependency in Maven
Cache sbt, maven, ivy dependencies
on_failure -> after_failure in travis.yml
Merge pull request #35 from shivaram/master

Cache sbt dependencies in travis.yml
converted tabs to spaces per project request
more formatting per committer request
and more formatting
Merge pull request #36 from RevolutionAnalytics/vectorize-examples

Vectorize examples
Move up Hadoop in pom.xml and add back protobufs
As Hadoop 1.0.4 doesn't use protobufs, we can't exclude
protobufs from Spark always. This change tries to order the dependencies
so that the shader first picks up Hadoop's protobufs over Mesos.
Merge pull request #48 from shivaram/master

Move up Hadoop in pom.xml and add back protobufs
Merge pull request #1 from amplab-extras/master

merge from SparkR master