include static encodeHex() method to purge commons-codec.jar

cacheword needs to have as few deps as possible, so purge this jar.  Thanks
to sqlcipher:

https://github.com/sqlcipher/android-database-sqlcipher/commit/817cff171c99bf6dfc654df3658dbb8af0d59e25

fixes #3663 https://dev.guardianproject.info/issues/3663
point to Android SDK for javadoc for android-support-v4.jar

If you have your Android SDK installed at /opt/android-sdk, then this will
make Eclipse automatically use the SDK's docs for the javadoc for methods
from the Support library.
replace heavy KDF iteration count function with one based on /proc/cpuinfo

The previous KDF iteration count measuring method took a long time to run
and depended on including spongycastle.  In the interest of keeping the
library as minimal as possible, it is good to remove dependencies.  In the
interest of usability, calculating the iteration count should be very fast.

fixes #3146 https://dev.guardianproject.info/issues/3146
fixes #3665 https://dev.guardianproject.info/issues/3665
fixes #492 https://dev.guardianproject.info/issues/492
minSdkVersion="9" without spongycastle

refs #3665 https://dev.guardianproject.info/issues/3665
add ant build targets: jar and javadoc

official ways to build the release jar and javadoc files.
standard script for setting up ant builds
fix all warnings
fetch-test-report ant target for getting JUnit report to Jenkins
set version to 0.1
added script for running jenkins builds
bump targetSdkVersion to latest (20)
clean up all XML (formatted and removed unused)
set up cachewordlib's manifest for merging, introduced in ADT v20

As of ADT v10 and gradle v0.10, it is possible to put stuff into a library
project's manifest, then have it included into the main project's manifest.
The main project has to add this to its project.properties to enable it:

  manifestmerger.enabled=true

https://android.googlesource.com/platform/sdk/+/a35f8af9eca38249b5c37391d7a7ae56c53251ad/manifmerger/src/com/android/manifmerger/ManifestMerger.java
https://stackoverflow.com/questions/10976635/using-the-new-manifestmerger-property-in-android/11234525#11234525
https://stackoverflow.com/questions/20346237/how-to-use-androidmanifest-merger
fix all javadoc warnings and errors
move SQLCipher helpers to separate library project

This means that the core of Cacheword can be shipped as a simple jar that
only depends on the Android Support v4 jar.  Also, for many users, they
will never need the SQLCipherV3MigrationHelper in their project at all
since they started with SQLCipher v3.

refs #3680 https://dev.guardianproject.info/issues/3680
move defaults out of XML and directly into the relevant classes

These constants are barely used, and are the only thing left that prevent
cacheword from being distributed only as a jar.

refs #3680 https://dev.guardianproject.info/issues/3680
move test classes into same package as the classes they test

This generally makes it easier to test the classes since the test classes
will have access to all methods/variables that are not declared private.
ignore all products of `android update` including proguard-project.txt
set sample minSdkVersion="11" to avoid using android-support-v4.jar
sort out android-support-v4.jar madness in Eclipse