CLASHES between security forces and protesters gripped Senegal's capital and other cities, the first widespread unrest over the delay of a presidential election that many fear could lead to protracted instability. Less than three weeks before the February 25 vote, parliament voted to push it back to December, sealing an extension of President Macky Sall's mandate that has raised concerns that one of the remaining democracies in coup-hit West Africa is under threat. In the capital Dakar, police in riot gear fired tear gas, stun grenades and what appeared to be rubber bullets at large crowds of protesters who were burning tyres…