Initial commit.
Add dummy svndump parser.
Ignore build artifacts with .gitignore.
Implement linear history parser.
Convert tabs to spaces.
Use platform-specific build flags.

* use apr-1-config to find apr include path;
* check Darwin ports include and lib paths;
* check Linux common include path for libsvn headers.
Fix build with libsvn 1.7 and older.
Notify about skipping revisions.
Fix directory replacing and deleting.
Do not use assignment in condition.
Quote node paths.
Strip reduntant linebreaks.
Simplify parser interface.

Do not expose parser internals in headers.
Add branch support.
Write blobs to backend only once.
Add functions for node kind and action parsing.
Add mark and revnum types.
Skip nodes for undefined branches.
Rename node action enum values.
Set correct mode for dir nodes.