README.md: provide detailed documentation

README.md

 # Unicode Character Data Tools
 
-The Unicode Character Data (UCD) Tools is a set of programs for working
-with the Unicode Character Data from unicode.org.
+- [Build Dependencies](#build-dependencies)
+  - [Debian](#debian)
+- [Building](#building)
+- [Updating the UCD Data](#updating-the-ucd-data)
+- [Bugs](#bugs)
+- [License Information](#license-information)
+
+----------
+
+The Unicode Character Data (UCD) Tools is a library for working with the
+Unicode Character Data from unicode.org.
+
+It provides a compact replacement for various wide-character C APIs. These can
+be used in Android applications, as the Android C library does not have full
+wide-character support.
+
+In addition to this it provides APIs for:
+-  querying the [Unicode General Category](http://www.unicode.org/reports/tr44/) values and groups;
+-  querying the [ISO 15924](http://www.unicode.org/iso15924/iso15924-codes.html) script;
+-  converting to upper, lower and title case.
+
+The following data sets are used for the data tables:
+-  [Unicode Character Data 6.3.0](ftp://www.unicode.org/Public/6.3.0/ucd/);
+-  [Klingon](http://www.evertype.com/standards/csur/klingon.html) [F8D0-F8FF].
+
+## Build Dependencies
+
+In order to build ucd-tools, you need:
+
+1.  a functional autotools system (`make`, `autoconf`, `automake` and `libtool`);
+2.  a functional c++ compiler.
+
+To build the documentation, you need:
+
+1.  the doxygen program to build the api documentation;
+2.  the dot program from the graphviz library to generate graphs in the api documentation.
+
+### Debian
+
+Core Dependencies:
+
+| Dependency       | Install                                               |
+|------------------|-------------------------------------------------------|
+| autotools        | `sudo apt-get install make autoconf automake libtool` |
+| c++ compiler     | `sudo apt-get install gcc g++`                        |
+
+Documentation Dependencies:
+
+| Dependency | Install                         |
+|------------|---------------------------------|
+| doxygen    | `sudo apt-get install doxygen`  |
+| graphviz   | `sudo apt-get install graphviz` |
+
+## Building
+
+UCD Tools supports the standard GNU autotools build system. The source code
+does not contain the generated `configure` files, so to build it you need to
+run:
+
+	./autogen.sh
+	./configure --prefix=/usr
+	make
+
+The tests can be run by using:
+
+	make check
+
+The program can be installed using:
+
+	sudo make install
+
+The documentation can be built using:
+
+	make html
+
+## Updating the UCD Data
+
+To re-generate the source files from the UCD data when a new version of
+unicode is released, you need to run:
+
+	./configure --prefix=/usr --with-unicode-version=VERSION
+	make ucd-update
+
+where `VERSION` is the Unicode version (e.g. `6.3.0`).
+
+## Bugs
+
+Report bugs to the [ucd-tools issues](https://github.com/rhdunn/ucd-tools/issues)
+page on GitHub.
+
+## License Information
+
+UCD Tools is released under the GPL version 3 or later license.