Added new flag DDVERBOSE  to DDLog so you can have another state.
DDTTYLogger: Allow to set default color profiles for all contexts at once

* Using `LOG_CONTEXT_ALL` will associate a color profile log messages from all contexts.
* Specific contexts can still set a different color profile on top.
Created 2 subspecs, Core and Extensions
Merge pull request #152 from bpoplauschi/extensionsSubspec

Created 2 subspecs, Core and Extensions
Merge pull request #146 from rivera-ernesto/ttylogger_defaultcolorprofile_forcontexts

DDTTYLogger: Allow to set default color profiles for all contexts at once
DDTTYLogger: By default apply setForegroundColor:backgroundColor:forFlag: to LOG_CONTEXT_ALL

Until now this method applied to only the default context `(0)`.

Follows #146.
Merge pull request #154 from rivera-ernesto/ttylogger_applytoallcontexts

DDTTYLogger: By default apply setForegroundColor:backgroundColor:forFlag: to LOG_CONTEXT_ALL
Implemented different logLevel per each logger as suggested by @rivera-ernesto
- addLogger method new method with logLevel param
- filtering via DDLoggerNode logLevel property
- actual filtering inside lt_log
Updated solution without code duplication
Merge pull request #151 from bpoplauschi/loggerLogLevel

Implemented different logLevel per each logger as suggested by @rivera-ernesto
Use DISPATCH_CURRENT_QUEUE_LABEL if available
Fix compilation on earlier SDKs

Check if DISPATCH_CURRENT_QUEUE_LABEL is defined.
Add comments
Suggested fixes: cleaner use of macros
Revert testing for DISPATCH_CURRENT_QUEUE_LABEL availability
It's MAX_ALLOWED, not MIN_REQUIRED
Merge pull request #156 from denivip/current-queue-ios7

Use DISPATCH_CURRENT_QUEUE_LABEL if available
Need to import UIKit/UIDevice.h
Update from VVerbose to Verbose and create a new level DEBUG
Merge commit 'ae306697dc79265c7617a8bba7b6ec48df445565'