Layout and Message updated for "appendStrings: false" option (#5)

The goal is for the console appender to send objects to the console
that are not serialized as strings when so requested with an
"appendStrings: false" option.

Internally, the appender will call "Layout.toMessageBits" to retrieve
bits of messages to send to the console. The layout delegates to
"Message.getFormattedParams" to create the appropriate bits.

JSONLayout and PatternLayout now need to implement "toMessageBits"
and "ConsoleAppender" still needs to call the "Layout.toMessageBits"
function.
ConsoleAppender support for "appendStrings: false" option (#5)

Layouts now implement the "toMessageBits" function instead of the
"toMessageString" function.

The console appender now preserves objects if so requested. The code
is slightly more complex to read and understand because it needs to
manipulate strings and objects instead of just strings but, hey,
that's worth it, isn't it?

The "console" shortcut should now sets the "appendStrings" flag
correctly, depending on whether it detects a node.js environment
(where preserving objects does not any real purpose) or a browser
environment (where the console gladly accepts objects).
ConsoleAppender: dropped temp debug "console.log" call (sigh)

The call had been introduced to trace the execution of the appender
while implementing support for "appendStrings: false". It's ironic
I suppose to use "console.log" to debug a library meant to help get
rid of these calls.
Config shortcut "console" now preserves objects in Web browsers (#5)

Loading Woodman with the "console" configuration shortcut in a Web
browser now behaves as the usual console for objects, meaning it
logs them as objects that can be expanded with the console.

Note objects are not preserved when Woodman is run in a node.js
environment. Also note that the code is a bit dumb for the time being
in that it assumes that not running in a node.js environment means
running in a Web browser whereas there are other JS runtimes around.
Added missing "repository" key to manifest file.
Removed unused variable from pattern layout
v0.6.0

Changelog:
- Added Woodman traces to precompiler library to monitor performances
- New --verbose option for the cli of the precompiler
- "appendStrings: false" in ConsoleAppender preserves objects (#5)
- Config shortcut "console" preserves objects by default in browsers