Removes Static Analyzer Warning

The function dispatch_source_create can return NULL and clang's static analyzer complains about this.

The code is moved inside a if-branch to execute it only when deleteTimer is not NULL.
Rectify mapping to ASL log level

1. Switch on logFlag rather than logLevel. logFlag varies per log messages,
   while logLevel is constant at file or even global scope.
2. Use the LOG_FLAG_* constants for each case clause.
Fixing more dispatch_get_current_queue warnings
Touching a few Xcode projects
Merge pull request #70 from rsobik/static_analyzer_fix

Removes Static Analyzer Warning
Merge branch 'master' of github.com:robbiehanson/CocoaLumberjack
Merge pull request #78 from kastiglione/asl-log-level

Rectify mapping to ASL log level
fix warning

"Commas at the end of enumerator lists are a C++11 extension"
fix implicit cast warnings

(Implicit conversion turns floating-point number into integer: 'double' to 'uint64_t' (aka 'unsigned long long'))
Fix typo which caused the file ivar to be set instead of function
Use the OS_OBJECT_USE_OBJC macro
update podspec to version 1.6.1

to coincide with tagging version 1.6.1 which incorporates changes that remove dispatch_get_current_queue() warnings.
Added NULL safety checks

These were reported as potential flaws by VeraCode scan.
Fixed potential memory leak
Merge pull request #92 from mattjgalloway/FixFunctionNameOnCopy

Fix typo which caused the file ivar to be set instead of function
Merge pull request #95 from cocoa-factory/master

tag 1.6.1 & update podspec to coincide
Merge pull request #90 from diederich/fix/warning

fix warning
Merge pull request #93 from mattjgalloway/Use_OS_OBJECT_USE_OBJC

Use the OS_OBJECT_USE_OBJC macro
Updating Xcode project files with recommended configuration settings
```clean_paths``` is deprecated in CocoaPods. Use preserve_paths instead.