- add error handling for all db operations
- refactoring Database.cc to make it more readable.
  add doc for Database.cc
  extract method copyDB(), initUserDB(), setPragmaOnMainDB()
- fix old timeoutCallback(), now named cb_saveUserDB()
  saveUserDB() should not be in the condition, because save can fail endlessly
  if file system have problem.
- no longer require main db to be a regular file. symlink should work fine.
- drop the dreaded overly reused class variable m_buffer. use meaningful names
  in current context.
- escape string in SQL statements
- update meson.build
  add prefix in PKGDATADIR
  define glib logging domain
  disable glib asserts for release build
- I will use so file version in git log.

BUG=https://code.google.com/p/pyzy/issues/detail?id=1
TEST=None

Review URL: https://codereview.appspot.com/6943055

BUG=None
TEST=Manual

Review URL: https://codereview.appspot.com/6307059

BUG=None
TEST=Manual

Review URL: https://codereview.appspot.com/6202056

replacing
- gchar - char
- gint - int, unsigned int, or size_t
- guint -> unsigned int or size_t
- guint8 -> unsigned char
- gboolean -> bool
- gsize -> size_t
- gpointer -> void *
- gconstpointer -> const void *
- gunichar -> unichar (typedef of int on PyZyUtil.h)

BUG=None
TEST=Run a test

Review URL: http://codereview.appspot.com/5367046

- Add many APIs to replace processKeyEvent.
- Remove pager related codes.

BUG=None
TEST=Run a test

Review URL: http://codereview.appspot.com/5314054

This CL don't modify files under debian/*.
Some files which is removed by http://codereview.appspot.com/5305041/ are also unmodified.

BUG=None
TEST=Manually

Review URL: http://codereview.appspot.com/5301043

BUG=
TEST=

Review URL: http://codereview.appspot.com/5235062