Add CapabilitiesList documentation

 - some of it was adapted from Alex Sheel comments on issue dogtagpki#693
   see dogtagpki#693

docs/usage/capabilities_list.md

@@ -0,0 +1,75 @@
+CapabilitiesList
+========================================
+
+Overview
+========================================
+
+**CapabilitiesList** is a Java application to list the capabilities
+of the "Mozilla-JSS" provider and other installed providers.
+It does it in two fashions brief and verbose. 
+
+It lets JSS contributors see what features the JDK implements (at different versions)
+and see what else we'd need to add in, to reach compatibility. Since we're 
+attempting to be a default crypto provider, it would be nice to ensure we're 
+mostly close to what the JDK provides. Hopefully other packages written to the
+JDK provider can have similar algorithms available under JSS and behave well. 
+Large gaps in coverage are likely an issue (such as #341 and #242).
+
+Usage
+========================================
+First build jss according to the instructions in jss/README.md
+You should see in the build directory tests_jss4.jar which is what
+contains the application along with the regular tests.
+From the jss/build directory execute
+./run_test org.mozilla.jss.tests.Capabilities
+
+and you should see a listings directory
+
+Running `tree listings` should produce something like
+
+listings/
+├── brief
+│   ├── Capabilities4JdkSASL.txt
+│   ├── Capabilities4Mozilla-JSS.txt
+│   ├── Capabilities4SunJCE.txt
+│   ├── Capabilities4SunJSSE.txt
+│   ├── Capabilities4SunPKCS11.txt
+│   ├── Capabilities4SunRsaSign.txt
+│   └── Capabilities4SUN.txt
+└── verbose
+ ├── Capabilities4JdkSASL.txt
+ ├── Capabilities4Mozilla-JSS.txt
+ ├── Capabilities4SunJCE.txt
+ ├── Capabilities4SunJSSE.txt
+ ├── Capabilities4SunPKCS11.txt
+ ├── Capabilities4SunRsaSign.txt
+ └── Capabilities4SUN.txt
+
+Here is a brief clip of Capabilities4Mozilla-JSS.txt
+ AlgorithmParameters : IvAlgorithmParameters
+ AlgorithmParameters : RC2AlgorithmParameters
+ AlgorithmParameters : RSAPSSAlgorithmParameters
+ Cipher : AES
+ Cipher : DES
+ Cipher : DESede
+ Alias: Cipher.DES3
+ Cipher : RC2
+ Cipher : RC4
+ Cipher : RSA
+ KeyFactory : DSA
+ KeyFactory : EC
+ KeyFactory : RSA
+ KeyGenerator : AES
+ KeyGenerator : DES
+ KeyGenerator : DESede
+ Alias: KeyGenerator.DES3
+ KeyGenerator : HmacSHA1
+ ... ommitted ...
+ KeyGenerator : HmacSHA512
+ KeyGenerator : KbkdfCounter
+ Alias: KeyGenerator.SP800-108-Counter
+ ... ommitted ...
+
+Notice that the Alias: lines have extra indentation which makes it
+easier to compare against the other providers.
+