common: Add header containing common BLE symbols
ll: Remove unnecessary ternary operator
ll: Rename LL_CRC_ADV to LL_CRCINIT_ADV

To avoid confusion.
ll: Document LL_CRCINIT_ADV
ll: Indent #defines following project codebase
ll: Use bdaddr_t instead of local address representation
common: Add advertising types enumeration
ll: Use adv_type_t instead of local representation
examples: Add long-advertisement example

This patch implements an example that advertises a long stream of data
by splitting this into multiple pages. Then the application advertises
each page for a small time. The peer is able to reconstruct the
original data by collecting each page.

To build it, first run the configure script to generate a config.h
header with the desired Bluetooth address and data to advertise.
bci: Change bci_init() return type