Major refactoring of the folders

Since we've decided to keep the two projects separated it's necessary
that if some one wants to clone the repository he has a clear idea of
what's going on here: in src/lib folder there are the three main
components of the library libgrive (drive, protocol and util); while
in the src/cli folder there's the command line interface tool that uses
the library. The CLI is called in the same way as the library (grive).

In this way, we can keep multiple clients using the same library in just
one repo..


These are the output of compiling the new tree:
`pearl :: Developer/grive/build » cmake ..
-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
-- Checking whether C compiler has -isysroot
-- Checking whether C compiler has -isysroot - yes
-- Checking whether C compiler supports OSX deployment target flag
-- Checking whether C compiler supports OSX deployment target flag - yes
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Checking whether CXX compiler has -isysroot
-- Checking whether CXX compiler has -isysroot - yes
-- Checking whether CXX compiler supports OSX deployment target flag
-- Checking whether CXX compiler supports OSX deployment target flag - yes
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- checking for module 'openssl'
--   found openssl, version 0.9.8j
-- Found OpenSSL: /usr/lib/libssl.dylib;/usr/lib/libcrypto.dylib (found version "0.9.8")
-- Found JSON-C: /usr/local/lib/libjson.dylib
-- Found CURL: /usr/lib/libcurl.dylib 
-- Found CppUnit: /usr/local/lib/libcppunit.dylib
-- Building unitary tests along with the library and the binary
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/massi/Developer/grive/build`


Compiling...
`pearl :: Developer/grive/build » make
Scanning dependencies of target grive
[  6%] Building CXX object src/lib/CMakeFiles/grive.dir/drive/Collection.cc.o
[ 13%] Building CXX object src/lib/CMakeFiles/grive.dir/drive/Drive.cc.o
[ 20%] Building CXX object src/lib/CMakeFiles/grive.dir/protocol/Download.cc.o
[ 26%] Building CXX object src/lib/CMakeFiles/grive.dir/protocol/HTTP.cc.o
[ 33%] Building CXX object src/lib/CMakeFiles/grive.dir/protocol/Json.cc.o
[ 40%] Building CXX object src/lib/CMakeFiles/grive.dir/protocol/OAuth2.cc.o
[ 46%] Building CXX object src/lib/CMakeFiles/grive.dir/util/Crypt.cc.o
[ 53%] Building CXX object src/lib/CMakeFiles/grive.dir/util/DateTime.cc.o
[ 60%] Building CXX object src/lib/CMakeFiles/grive.dir/util/OS.cc.o
[ 66%] Building CXX object src/lib/CMakeFiles/grive.dir/util/Path.cc.o
Linking CXX shared library libgrive.dylib
[ 66%] Built target grive
Scanning dependencies of target grive_executable
[ 73%] Building CXX object src/cli/CMakeFiles/grive_executable.dir/main.cc.o
Linking CXX executable grive
[ 73%] Built target grive_executable
Scanning dependencies of target unittest
[ 80%] Building CXX object test/CMakeFiles/unittest.dir/UnitTest.cc.o
[ 86%] Building CXX object test/CMakeFiles/unittest.dir/util/DateTimeTest.cc.o
[ 93%] Building CXX object test/CMakeFiles/unittest.dir/util/FunctionTest.cc.o
[100%] Building CXX object test/CMakeFiles/unittest.dir/util/PathTest.cc.o
Linking CXX executable unittest
[100%] Built target unittest`


The output of ldd
`pearl :: Developer/grive/build » otool -L ./src/cli/grive 
./src/cli/grive:
	/Users/massi/Developer/grive/build/src/lib/libgrive.0.dylib (compatibility version 0.0.0, current version 0.0.1)
	/usr/lib/libcurl.4.dylib (compatibility version 7.0.0, current version 7.0.0)
	/usr/local/lib/libjson.0.dylib (compatibility version 1.0.0, current version 1.1.0)
	/usr/lib/libssl.0.9.8.dylib (compatibility version 0.9.8, current version 44.0.0)
	/usr/lib/libcrypto.0.9.8.dylib (compatibility version 0.9.8, current version 44.0.0)
	/usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 52.0.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 159.1.0)`


Running the unittest..
`pearl :: Developer/grive/build » ./test/unittest 
........


OK (8 tests)`


Running the grive CLI..
`pearl :: Developer/grive/build 130 » ./src/cli/grive -a
-----------------------
Please go to this URL and get an authenication code:

https://accounts.google.com/o/oauth2/auth?scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile+https%3A%2F%2Fdocs.google.com%2Ffeeds%2F+https%3A%2F%2Fdocs.googleusercontent.com%2F+https%3A%2F%2Fspreadsheets.google.com%2Ffeeds%2F&redirect_uri=urn:ietf:wg:oauth:2.0:oob&response_type=code&client_id=22314510474.apps.googleusercontent.com

-----------------------
Please input the authenication code here
^C`


Installing...
`pearl :: Developer/grive/build 130 » make install
[ 66%] Built target grive
[ 73%] Built target grive_executable
[100%] Built target unittest
Install the project...
-- Install configuration: ""
-- Installing: /usr/local/lib/libgrive.0.0.1.dylib
-- Up-to-date: /usr/local/lib/libgrive.0.dylib
-- Up-to-date: /usr/local/lib/libgrive.dylib
-- Up-to-date: /usr/local/include/grive/drive/Collection.hh
-- Up-to-date: /usr/local/include/grive/drive/Drive.hh
-- Up-to-date: /usr/local/include/grive/protocol/Download.hh
-- Up-to-date: /usr/local/include/grive/protocol/HTTP.hh
-- Up-to-date: /usr/local/include/grive/protocol/Json.hh
-- Up-to-date: /usr/local/include/grive/protocol/OAuth2.hh
-- Up-to-date: /usr/local/include/grive/util/Crypt.hh
-- Up-to-date: /usr/local/include/grive/util/DateTime.hh
-- Up-to-date: /usr/local/include/grive/util/Function.hh
-- Up-to-date: /usr/local/include/grive/util/OS.hh
-- Up-to-date: /usr/local/include/grive/util/Path.hh
-- Installing: /usr/local/bin/grive
`