Fix inconsistent line endings introduced in r446.

git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@451 812d1f90-f944-d88a-411a-122bdc93e1ea
Remove executable path from mapping search path.
This obviates the need to pass the executable path through IwyuAction into InitGlobals

git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@452 812d1f90-f944-d88a-411a-122bdc93e1ea
Clean up handling of mapping file search paths. The current policy is to treat --mapping_file switches as relative to the current dir or absolute. Ref directives are evaluated relative to the current directory and then relative to the containing mapping file, and multiple levels of refs build up the mapping file search path incrementally.
- Remove hard-coded mapping search path in iwyu_globals.cc
- Remove AddMappingFileSearchPath
- Add private AddMappingsFromFile to handle search path building
- Push search path scanning out into free function FindFileInSearchPath
- Less, but more focused logging.
- Fix indentation in iwyu_include_picker.cc
- Simplify parsing code by making current_node a Node* instead of a Node&


git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@453 812d1f90-f944-d88a-411a-122bdc93e1ea
Fix a style guide violation introduced in r449.
Unused parameters should not be omitted, only commented out.

git-svn-id: http://include-what-you-use.googlecode.com/svn/trunk@454 812d1f90-f944-d88a-411a-122bdc93e1ea