Various doc improvements (#248)
- Rename all the ugly template parameters (too long and/or starting
with an underscore).
- Rename function parameters starting with an underscore.
- Extend the doc for many classes.
- Use LaTeX-style O(...) expressions only for the complicated ones.
- A lot of small unification changes.
- Small fixes.
- Some other improvements.

 INCLUDE_DIRECTORIES(

   ${CMAKE_SOURCE_DIR}

   ${CMAKE_BINARY_DIR}

 )

 LINK_DIRECTORIES(${CMAKE_BINARY_DIR}/lemon)

 SET(DEMOS

   arg_parser_demo

   graph_to_eps_demo

   lgf_demo)

 FOREACH(DEMO_NAME ${DEMOS})

   ADD_EXECUTABLE(${DEMO_NAME} ${DEMO_NAME}.cc)

   TARGET_LINK_LIBRARIES(${DEMO_NAME} lemon)

 ENDFOREACH(DEMO_NAME)